Patent Application
20220220587
The present disclosure relates generally to alloyed materials, and more specifically to 3-D printable alloys.
The present disclosure relates generally to alloys, and more specifically to aluminum alloys and structures of aluminum alloys.
Additive Manufacturing (AM) processes involve the use of a stored geometrical model for accumulating layered materials on a “build plate” to produce three-dimensional (3-D) objects having features defined by the model. AM techniques are capable of printing complex components using a wide variety of materials. A 3-D object is fabricated based on a computer-aided design (CAD) model. The AM process can manufacture a solid three-dimensional object directly from the CAD model without additional tooling.
One example of an AM process is powder bed fusion (PBF), which uses a laser, electron beam, or other source of energy to sinter or melt metallic powder deposited in a powder bed, thereby consolidating powder particles together in targeted areas to produce a 3-D structure having the desired geometry. Different materials or combinations of materials, such as metals, plastics, and ceramics, may be used in PBF to create the 3-D object. Other more advanced AM techniques, including those discussed further below, are also available or under current development, and each may be applicable to the present disclosure.
Another example of an AM process is called Binder Jet (BJ) process that uses a powder bed (similar to PBF) in which metallic powder is spread in layers and bonded by using an organic binder. The resulting part is a green part which requires burning off the binder and sintering to consolidate the layers into full density. The metallic powder material can have the same chemical composition and similar physical characteristics as PBF powders.
Another example of an AM process is called Directed Energy Deposition (DED). DED is an AM technology that uses a laser, electron beam, plasma, or other method of energy supply, such as those in Tungsten Inert Gas (TIG), or Metal Inert Gas (MIG) welding to melt the metallic powder or wire and rod, thereby transforming it into a solid metal object. Unlike many AM technologies, DED is not based on a powder bed. Instead, DED uses a feed nozzle to propel the powder or mechanical feed system to deliver wire and rod into the laser beam, electron beam, plasma beam, or other energy stream. The powdered metal or the wire and rod are then fused by the respective energy beam. While supports or a freeform substrate may in some cases be used to maintain the structure being built, almost all the raw material (powder, wire, or rod) in DED is transformed into solid metal, and consequently, little waste powder is left to recycle. Using a layer by layer strategy, the print head, comprised of the energy beam or stream and the raw material feed system, can scan the substrate to deposit successive layers directly from a CAD model.
PBF, BJ, DED, and other AM processes may use various raw materials such as metallic powders, wires, or rods. The raw material may be made from various metallic materials. Metallic materials may include, for example, aluminum, or alloys of aluminum. It may be advantageous to use alloys of aluminum that have properties that improve functionality within AM processes. For example, particle shape, powder size, packing density, melting point, flowability, stiffness, porosity, surface texture, density electrostatic charge, as well as other physical and chemical properties may impact how well an aluminum alloy performs as a material for AM. Similarly, raw materials for AM processes can be in the form of wire and rod whose chemical composition and physical characteristics may impact the performance of the material. Some alloys may impact one or more of these or other traits that affect the performance of the alloy for AM.
One or more aspects of the present disclosure may be described in the context of the related technology. None of the aspects described herein are to be construed as an admission of prior art, unless explicitly stated herein.
Several aspects of one or more alloys and compositions of alloys, as well as methods of making and/or using the same, are described herein. For example, one or more alloys or compositions thereof may be aluminum alloys. The one or more alloys may be used in three-dimensional (3-D) printing and/or additive manufacturing to produce additively manufactured structures with the one of more alloys. Illustratively, an alloy may include a composition containing a plurality of materials (e.g., elements, metals, etc.). An alloy in accordance with an aspect of the present disclosure comprises cobalt, titanium, silicon, magnesium, zinc, manganese, zirconium, and aluminum, wherein a structure of the alloy as printed by a 3D printing process has a yield strength of at least 300 Megapascals and an elongation of at least 4 percent.
Such an alloy may further optionally include where the 3D printing process includes a cooling rate greater than 1000 degrees Celsius per second, the 3D printing process including at least one of Laser-Powder Bed Fusion, Electron Beam Powder Bed Fusion, or Directed Energy Deposition, the alloy consisting essentially of the cobalt, titanium, silicon, magnesium, zinc, manganese, zirconium, and aluminum, the structure of the alloy has an elongation of at least 6 percent, at least 7 percent, the structure having a yield strength of at least 325 Megapascals, at least 350 Megapascals, at least 360 Megapascals, and the aluminum being between 87 percent by weight of the alloy and 95 percent by weight of the alloy.
An alloy in accordance with an aspect of the disclosure may comprise cobalt (Co), wherein an amount of the Co in the alloy is less than or equal to about 1.0% by weight of the alloy and greater than or equal to about 0.2% by weight of the alloy, titanium (Ti) wherein an amount of the Ti in the alloy is less than or equal to about 0.5% by weight of the alloy and greater than or equal to about 0.05% by weight of the alloy, silicon (Si) wherein an amount of the Si in the alloy is less than or equal to about 3% by weight of the alloy and greater than or equal to about 1% by weight of the alloy, magnesium (Mg) wherein an amount of the Mg in the alloy is less than or equal to about 5% by weight of the alloy and greater than or equal to about 1% by weight of the alloy, zinc (Zn) wherein an amount of the Zn in the alloy is less than or equal to about 2% by weight of the alloy and greater than or equal to about 0.1% by weight of the alloy, zirconium (Zr) wherein an amount of the Zr in the alloy is less than or equal to about 0.5% by weight of the alloy and greater than or equal to about 0.05% by weight of the alloy, manganese (Mn) wherein an amount of the Mn in the alloy is less than or equal to about 1.0% by weight of the alloy and greater than or equal to about 0.2% by weight of the alloy, and aluminum (Al).
Such an alloy may further be produced by a 3D printing process, wherein the 3D printing process includes a cooling rate greater than 1000 degrees Celsius per second, and the 3D printing process includes at least one of Laser-Powder Bed Fusion, Electron Beam Powder Bed Fusion, or Directed Energy Deposition.
Such an alloy may consist essentially of the Co, the Ti, the Si, the Mg, the Zn, the Mn, the Zr, and the Al. Such an alloy may have an elongation of at least 7 percent, and may include Al between 87 percent by weight of the alloy and 95 percent by weight of the alloy.
It will be understood that other aspects of alloys will become readily apparent to those of ordinary skill in the art from the following detailed description, wherein it is shown and described only several embodiments by way of illustration. As will be realized by those of ordinary skill in the art, the manufactured structures and the methods for manufacturing these structures are capable of other and different embodiments, and its several details are capable of modification in various other respects, all without departing from the disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
Various aspects of alloys that may be used for additive manufacturing, for example, in automotive, aerospace, and/or other engineering contexts are presented in the detailed description by way of example, and not by way of limitation, in the accompanying drawings, wherein:
The detailed description set forth below in connection with the appended drawings is intended to provide a description of various exemplary embodiments of aluminum alloys are not intended to represent the only embodiments in which the disclosure may be practiced. The term “exemplary” used throughout this disclosure means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments presented in this disclosure. The detailed description includes specific details for the purpose of providing a thorough and complete disclosure that fully conveys the scope of the disclosure to those of ordinary skill in the art. However, the techniques and approaches of the present disclosure may be practiced without these specific details. In some instances, well-known structures and components may be shown in block diagram form, or omitted entirely, in order to avoid obscuring the various concepts presented throughout this disclosure.
Metal alloys, such as aluminum alloys, are often utilized in various engineering applications, such as automotive and aerospace. In many applications, these engineering applications may benefit from alloys that offer high performance and sustainability. Moreover, alloys that are economical may be more advantageous, e.g., as alloys that include rare and/or expensive elements may be impractical for relatively large-scale and/or commercial applications.
While some alloys that fulfill the aforementioned conditions exist, these existing alloys are mostly unsuitable for additive manufacturing (AM) applications, such as Selective Laser Melting (SLM) and/or Powder Bed Fusion (PBF). For example, AM processes with alloys commonly used for traditional manufacturing (i.e., non-AM manufacturing) may result in microstructure and/or other characteristics of these alloys that are unacceptable—e.g., by resulting in defective and/or unsafe products.
AM processes may include a very small melt pool and/or very high cooling rate from liquid to solid states for alloys, e.g., in comparison with traditional manufacturing processes. Therefore, alloys used in AM processes may be expected to develop microstructure and/or other characteristics (e.g., through the relatively small melt pool and/or relatively high cooling rate) that yield high strength, ductility, fracture toughness, fatigue strength, corrosion resistance, and/or elevated temperature strength and, therefore, result in satisfactory products.
In view of the foregoing, there exists a need for alloys that are high performance and economically feasible for AM in various automotive, aerospace, and/or other engineering applications. The present disclosure describes alloys that may be implemented in AM processes, such as SLM, PBF, DED, and others. In this way, for example, additively manufactured structures of the alloys disclosed in this disclosure may be produced. The alloys of the present disclosure may provide improved properties for AM in automotive, aerospace, and/or other engineering applications. The alloys may yield improved performance in AM contexts, such as one or more of high strength (e.g., yield strength), ductility, fracture toughness, fatigue strength, corrosion resistance, elevated temperature strength, percent elongation, and/or any combination thereof. Furthermore, application of the alloys of the present disclosure may be economically feasible, for example, in a commercial context and/or production scale for AM in automotive, aerospace, and/or other engineering applications.
AlSi10Mg (AA 4046) is an aluminum alloy that may be used for Additive Manufacturing (AM) techniques, such as Selective Laser Melting (SLM) and/or Powder Bed Fusion (PBF). However, AA 4046 is primarily a welding alloy for joining automotive aluminum parts. When processed by additive manufacturing, this alloy yields moderate strength but poor ductility. AA 4046 has good welding properties where the weld pool is large and cooling rate is relatively slow. Additionally, AA 4046 may be used in cases where a joint design can tolerate poor properties. For example, some environments may cause a reduction in fatigue life of a component due to a corrosive environment compared to the performance of the component in air. The reduction in fatigue life may be referred to as a knockdown factor. However, in AM, the whole part is built with micro-welds with extremely small weld pools and rapid melting and cooling.
Accordingly, with AM, there should be little or no compromise through design knockdown. Extremely high attention has been placed on the improvement of properties of AA 4046, resulting in a voluminous array of investigations without significant property improvements for engineering applications that require high performance and reliability. Still, the tested mechanical properties of AA 4046 may be inferior to those commonly used in wrought and cast form for high-strength applications. In addition, some aluminum alloys are unavailable and/or impractical for commercial use in AM, such as aluminum alloys in the 6000 and 7000 series.
Some high-performance aluminum alloys have been developed that may differ from AA 4046, aluminum alloys in the 6000 and 7000 series, and/or other commercially available aluminum alloys. Such high-performance alloys may include Scalmalloy® and A205. However, the applications of various high-performance aluminum alloys, including Scalmalloy® and A205, may be economically prohibitive in AM contexts.
In view of the foregoing, there exists a need for alloys that are high performance and economically feasible for AM in various automotive, aerospace, and/or other engineering applications. The present disclosure describes alloys that may be implemented in AM processes, such as SLM, PBF, DED, and others. In this way, for example, additively manufactured structures of the alloys disclosed in this invention may be produced. The alloys of the present disclosure may provide improved properties for AM in automotive, aerospace, and/or other engineering applications. The alloys may yield improved performance in AM contexts, such as one or more of high strength (e.g., yield strength), ductility, fracture toughness, fatigue strength, corrosion resistance, elevated temperature strength, percent elongation, and/or any combination thereof. Furthermore, application of the alloys of the present disclosure may be economically feasible, for example, in a commercial context and/or production scale for AM in automotive, aerospace, and/or other engineering applications.
In an aspect, high-performance aluminum alloys are described. Crashworthiness is a combination of tensile, shear, and compression strengths that make up a material's crash performance. The analytical and experimental data are utilized by a variety of industries (e.g., automotive) while designing and engineering structures incorporating the materials.
High-performance aluminum alloys processed with conventional techniques (e.g., non-AM processes) may obtain various properties through one or combination of the following processes: solid solution strengthening, strain hardening, precipitation strengthening, and/or dispersion strengthening. The processes of solid solution strengthening, strain hardening, precipitation strengthening, grain or phase boundary strengthening, and/or dispersion strengthening may take place during solidification, subsequent thermal processing, intermediate cold working, or some combination of these.
Solidification processes and subsequent cooling in solid state in AM may differ from those processes occurring through conventional techniques. For example, the solidification in PBF processing occurs on a microscale, layer by layer, with each layer undergoing one or more melting, solidification, and cooling cycles. In such a process, melting may begin at approximately 610° C. and may conclude at approximately 696° C. Due to the small size of the melt pool, the cooling rate is extremely high relative to conventional techniques—e.g., the cooling rate may be from approximately 103° C./second (s) to approximately 106° C./s. Therefore, non-equilibrium thermodynamics and phase transformation kinetics may become the dominant drivers during AM, thereby making alloys exhibit different properties with AM, such as through inheriting element supersaturation and alloy partitioning.
Not all alloys (e.g., AA 4046, etc.) may be suitable for the rapid solidification through AM, which may include relatively small weld pools (and may include a cooling rate of approximately 1000 degrees Celsius per second (103° C./s) to approximately 1 million degrees Celsius per second (106° C./s). The present disclosure describes alloys that may provide high performance with AM, e.g., in comparison to currently available alloys. The performance of these alloys of the present disclosure may be improved in the as-printed state, e.g., after undergoing thermal processing (post AM), or some combination of both in the as-printed state and after undergoing thermal processing.
In one exemplary configuration, one or more alloys of the present disclosure may be tailored for superior strengthening where the one or more alloys would have high ultimate and tensile strength at room and elevated temperature. In another exemplary configuration, one or more of the alloys of the present disclosure may be designed for superior ductility where the one or more alloys would have high elongation at room and elevated temperatures.
The nominal chemical composition of the common AA 4046 includes 11% silicon (Si), 0.55% iron (Fe), 0.45% manganese (Mn), 0.45% magnesium (Mg), and balance aluminum (Al). The as-printed tensile properties of AA 4046 are up to 6% elongation, up to 301 megapascal (MPa) yield strength, and up to 459 MPa ultimate tensile strength. High-performance aluminum alloys, such as Scalmalloy®, have nominal chemical compositions of 4.5% Mg, 0.7% scandium (Sc), 0.3% zirconium (Zr), 0.5% Mn, with heat-treated properties of up to 13% elongation, up to 469 MPa yield strength, and up to 495 MPa ultimate tensile strength. However, the aforementioned high-performance aluminum alloys are economically infeasible for production scale and/or commercial consumer applications (e.g., automotive applications).
According to some configurations, one or more alloys of the present disclosure may be configured with elongation percentage exceeding that of some existing aluminum alloys, such as AA 4046. While the advertised and tested elongation percentage of AA 4046 is approximately 6% and 4%, respectively, an elongation of one or more alloys of the present disclosure may be approximately 8%. Therefore, one or more alloys described herein may exceed the elongation percentage of the conventional AA 4046 by approximately 2%, e.g., in the as-printed condition. Post-processing techniques, such as heat treatment and/or surface (shot) peening, may further increase the elongation percentage of the one or more alloys described herein. For example, heat treatment may include treating an aluminum alloy as described herein at a temperature between approximately 100° C. to approximately 400° C. for a time of approximately 30 minutes to approximately 30 hours.
In addition, the strength(s) of the one or more alloys described herein may exceed that of some existing aluminum alloys. For example, one or more alloys described herein may have an average yield strength of at least 300 MPa, at least 325 MPa, at least 350 MPa, or at least 363 MPa, depending on the composition and manufacture of the alloy. This average yield strength may exceed some aluminum alloys of the 7000 series (e.g., Al 7075) in AM. The alloying elements in the aluminum matrix may create strengthening mechanisms intrinsic to chemistry and, through AM, the resultant material including the alloying elements of the present disclosure may be approximately 80% stronger than AA 4046. One or more alloys of the present disclosure may derive strength(s) through solid solution strengthening, micro-precipitation hardening, nano-precipitation hardening, reduced grain size, and/or strain hardening. Further, an alloy of the present disclosure may have an elongation of at least 4 percent, at least 5 percent, at least 6 percent, at least 7 percent, or up to 10 percent, depending on the composition and manufacture of the alloy. Aluminum may make up between 85 and 95 percent by weight of the alloy, and may be between 87 and 95 percent by weight of the alloy as desired.
One or more alloys of the present disclosure may be specifically designed in order to accommodate the rapid melting, solidification, and/or cooling experienced by alloys in AM (e.g., PBF process). For example, the alloying elements and concentrations thereof may be configured such that intermetallics may be formed with other alloying elements during rapid cooling. Further, the alloying elements and concentrations thereof may be configured based on the liquid and/or solid solubilities of the alloying elements in the aluminum matrix. The alloying elements and concentrations thereof may be configured such that the alloying elements may form supersaturated solid solutions and/or nano-precipitates after rapid solidification and cooling during AM (e.g., PBF process). The alloying elements and the concentrations thereof may be configured to form intermetallics and the phases thereof during subsequent thermal processing, for example, including precipitation heat treatment and/or Hot Isostatic Pressing (HIP). Finally, the alloying elements and concentrations thereof may be configured to form targeted specific intermetallics during rapid solidification and cooling such that the phases formed thereby may enhance the performance of the one or more alloys of the present disclosure. Additionally, the configurations of the alloying elements and the concentrations thereof may result in the formation of phases during subsequent thermal processing that improves the mechanical performance of the one or more alloys of the present disclosure.
Example elements that may be used to form aluminum alloys in some examples may include cobalt (Co), silicon (Si), Mg, and balance Al. In some further configurations, example elements that may be used to form aluminum alloys in some further examples may include nickel (Ni), titanium (Ti), zinc (Zn), Zr, Mn, or some combination of these elements (or other elements as discussed here). Configuring one or more alloys of the present disclosure with Co may contribute to precipitation hardening of the one or more alloys. Exemplary concentrations of Co may be 0.2-1% by weight of an alloy described herein. Configuring one or more alloys of the present disclosure with Si may contribute to precipitation hardening. Exemplary concentrations of Si may be 1-3% by weight of an alloy described herein. Configuring one or more alloys of the present disclosure with Zr may contribute to precipitation hardening. Exemplary concentrations of Zr may be 0.05-0.5% by weight of an alloy described herein. Configuring one or more alloys of the present disclosure with Ti may contribute to solid solution strengthening. Exemplary concentrations of Ti may be 0.05-0.5% by weight of an alloy described herein. Configuring one or more alloys of the present disclosure with Mg may contribute to solid solution strengthening. Exemplary concentrations of Mg may be 1-5% by weight of an alloy described herein. Configuring one or more alloys of the present disclosure with Zn may contribute to solid solution strengthening. Exemplary concentrations of Zn may be 0.1-2% by weight of an alloy described herein. Configuring one or more alloys of the present disclosure with Mn may contribute to solid solution strengthening. Exemplary concentrations of Mn may be 0.2-1% by weight of an alloy described herein. One or more alloys of the present disclosure may include a balance of Al, which may include at most 0.1% by weight of trace elements.
In this example, the 3-D printer system is a powder-bed fusion (PBF) system 100.
PBF System 100 may be an electron-beam PBF system 100, a laser PBF system 100, or other type of PBF system 100. Further, other types of 3-D printing, such as Directed Energy Deposition, Selective Laser Melting, Binder Jet, etc., may be employed without departing from the scope of the present disclosure.
PBF system 100 can include a depositor 101 that can deposit each layer of metal powder, an energy beam source 103 that can generate an energy beam, a deflector 105 that can apply the energy beam to fuse the powder material, and a build plate 107 that can support one or more build pieces, such as a build piece 109. Although the terms “fuse” and/or “fusing” are used to describe the mechanical coupling of the powder particles, other mechanical actions, e.g., sintering, melting, and/or other electrical, mechanical, electromechanical, electrochemical, and/or chemical coupling methods are envisioned as being within the scope of the present disclosure.
PBF system 100 can also include a build floor 111 positioned within a powder bed receptacle. The walls 112 of the powder bed receptacle generally define the boundaries of the powder bed receptacle, which is sandwiched between the walls 112 from the side and abuts a portion of the build floor 111 below. Build floor 111 can progressively lower build plate 107 so that depositor 101 can deposit a next layer. The entire mechanism may reside in a chamber 113 that can enclose the other components, thereby protecting the equipment, enabling atmospheric and temperature regulation and mitigating contamination risks. Depositor 101 can include a hopper 115 that contains a powder 117, such as a metal powder, and a leveler 119 that can level the top of each layer of deposited powder.
AM processes may use various metallic powders, such as one or more alloys of the present disclosure. The particular embodiments illustrated in
According to some examples of the present disclosure, an aluminum alloy used in PBF system 100 may be a composition that includes a balance of Al, Mg that is 0 to 5% by weight of the composition, Si that is 0.5 to 4% by weight of the composition, and Co that is 0.2 to 5% by weight of the composition. In a specific configuration, the Mg may be 1 to 5% by weight of the composition, Si may be 1 to 3% by weight of the composition, and Co may be 0.2 to 1% by weight of the composition.
In some further configurations, the composition may further include at least one selected from a group of Ni, Ti, Zn, Zr, and/or Mn. In one example, the composition may include Ti that is least 0.05% by weight of the composition. The composition may include up to 0.5% by weight of Ti. In another example, the composition may include Zr that is at least 0.05% by weight of the composition. The composition may include up to 0.5% by weight of Zr. In a further example, the composition may include Mn that is up to 1% by weight of the composition. The composition may include at least 0.2% by weight of Mn. In still another example, the composition may include Ni that is 1 to 5% by weight of the composition. In yet a further example, the composition may include Zn that is 0.1 to 2% by weight of the composition. In some examples, the composition may include up to approximately 0.1% by weight of trace impurities cumulatively, and 0.01% individually (e.g., in each individual element that is alloyed with the balance of Al).
According to some configurations of the present disclosure, an alloy may comprise: a composition that includes: magnesium (Mg) that is approximately 1 to 5% by weight of the composition; silicon (Si) that is approximately 1 to 3% by weight of the composition; cobalt (Co) that is approximately 0.2 to 1% by weight of the composition; and aluminum (Al) that is a balance of the composition. In one configuration, the composition may further include at least one selected from: nickel (Ni); titanium (Ti); zinc (Zn); zirconium (Zr); and manganese (Mn). In one configuration, the composition includes up to approximately 5% by weight of the Ni. In one configuration, the composition includes at least approximately 1% by weight of the Ni. In one configuration, the composition includes up to approximately 0.5% by weight of the Ti. In one configuration, the composition includes at least 0.05% by weight of the Ti. In one configuration, the composition includes up to approximately 2% by weight of the Zn. In one configuration, the composition includes at least 0.1% by weight of the Zn. In one configuration, the composition includes up to approximately 0.5% by weight of the Zr. In one configuration, the composition includes at least 0.05% by weight of the Zr. In one configuration, the composition includes up to approximately 1% by weight of the Mn. In one configuration, the composition includes at least 0.2% by weight of the Mn. In one configuration, the composition includes all of the elements listed above (Al, Mg, Si, Co, Ni, Ti, Zn, Zr, and Mn). In one configuration, the balance of the Al of the composition includes up to approximately 0.1% by weight of trace impurities.
In one configuration, the composition includes all of the elements listed herein (Al, Mg, Si, Co, Ni, Ti, Zn, Zr, and Mn). In one configuration, the composition includes up to approximately 0.1% by weight of trace impurities cumulatively, and 0.01% individually (e.g., in each individual element that is alloyed with the balance of Al).
Prior to use in PBF system 100, the elements of an alloy, which may be an aluminum alloy, may be combined into a composition according to one of the examples/configurations described herein. For example, the elements in respective concentrations described in one of the examples/configurations of the present disclosure may be combined when the elements are molten. The composition may be mixed while the elements are molten, e.g., in order to promote even distribution of each element with the balance of the base material, which may be aluminum. The molten composition may be cooled and atomized. Atomization of the composition may yield a metallic powder that includes the elements of the one of the examples/configurations of the present disclosure, and can be used in additive manufacturing systems such as PBF system 100. Referring specifically to
In various embodiments, the deflector 105 can include one or more gimbals and actuators that can rotate and/or translate the energy beam source to position the energy beam. In various embodiments, energy beam source 103 and/or deflector 105 can modulate the energy beam, e.g., turn the energy beam on and off as the deflector scans so that the energy beam is applied only in the appropriate areas of the powder layer. For example, in various embodiments, the energy beam can be modulated by a digital signal processor (DSP).
In an aspect of the present disclosure, control devices and/or elements, including computer software, may be coupled to PBF system 100 to control one or more components within PBF system 100. Such a device may be a computer 150, which may include one or more components that may assist in the control of PBF system 100. Computer 150 may communicate with a PBF system 100, and/or other AM systems, via one or more interfaces 151. The computer 150 and/or interface 151 are examples of devices that may be configured to implement the various methods described herein, that may assist in controlling PBF system 100 and/or other AM systems.
In an aspect of the present disclosure, computer 150 may comprise at least one processor 152, memory 154, signal detector 156, a digital signal processor (DSP) 158, and one or more user interfaces 160. Computer 150 may include additional components without departing from the scope of the present disclosure.
Processor 152 may assist in the control and/or operation of PBF system 100. The processor 152 may also be referred to as a central processing unit (CPU). Memory 154, which may include both read-only memory (ROM) and random access memory (RAM), may provide instructions and/or data to the processor 152. A portion of the memory 154 may also include non-volatile random access memory (NVRAM). The processor 152 typically performs logical and arithmetic operations based on program instructions stored within the memory 154. The instructions in the memory 154 may be executable (by the processor 152, for example) to implement the methods described herein.
The processor 152 may comprise or be a component of a processing system implemented with one or more processors. The one or more processors may be implemented with any combination of general-purpose microprocessors, microcontrollers, digital signal processors (DSPs), floating point gate arrays (FPGAs), programmable logic devices (PLDs), controllers, state machines, gated logic, discrete hardware components, dedicated hardware finite state machines, or any other suitable entities that can perform calculations or other manipulations of information.
The processor 152 may also include machine-readable media for storing software. Software shall be construed broadly to mean any type of instructions, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Instructions may include code (e.g., in source code format, binary code format, executable code format, RS-274 instructions (G-code), numerical control (NC) programming language, and/or any other suitable format of code). The instructions, when executed by the one or more processors, cause the processing system to perform the various functions described herein.
Signal detector 156 may be used to detect and quantify any level of signals received by the computer 150 for use by the processor 152 and/or other components of the computer 150. The signal detector 156 may detect such signals as energy beam source 103 power, deflector 105 position, build floor 111 height, amount of powder 117 remaining in depositor 101, leveler 119 position, and other signals. DSP 158 may be used in processing signals received by the computer 150. The DSP 158 may be configured to generate instructions and/or packets of instructions for transmission to PBF system 100.
The user interface 160 may comprise a keypad, a pointing device, and/or a display. The user interface 160 may include any element or component that conveys information to a user of the computer 150 and/or receives input from the user.
The various components of the computer 150 may be coupled together by interface 151, which may include, e.g., a bus system. The interface 151 may include a data bus, for example, as well as a power bus, a control signal bus, and a status signal bus in addition to the data bus. Components of the computer 150 may be coupled together or accept or provide inputs to each other using some other mechanism.
Although a number of separate components are illustrated in
Alloy Structures
In
In
Aspects of the present disclosure can include substitutional alloys, interstitial alloys, and combination alloys with combinations of substitutional/interstitial solutes in a given alloy. Further, a base material (such as base material 202, 212, and 222) may include one or more elements, e.g., the base material may be a plurality of two materials, e.g., copper (Cu) and zinc (Zn), without departing from the scope of the present disclosure. Although the use of “base” in base material may mean that the base material is the majority of the composition of the alloy, such meaning is not necessarily always the case in many aspects of the present disclosure. In various embodiments, base material may indicate an underlying structure of the alloy, since different materials have different atomic arrangements, e.g., fcc, bcc, cubic, hcp, etc.
In an aspect of the present disclosure, solutes can be included with a base material to change one or more properties that the base material exhibits. For example, and not by way of limitation, carbon (C) may be added to Fe to increase strength and reduce oxidation. In other words, solutes may be added as impurities to a base material to change the characteristics of the bonds between atoms within a base material structure.
In many materials, and in many alloys, there are several basic characteristics that determine the suitability of that material/alloy for a given application. For example, and not by way of limitation, strength, heat resistance, and ductility are three characteristics that may be of interest in certain applications.
As shown in
The resultant alloy structure, whether interstitial, substitutional, polycrystalline, amorphous, or various combinations, provides different values for the properties of the alloy than the properties of the base material in a pure form. For example, alloying gold (Au) with silver (Ag) makes the resultant alloy harder, i.e., the resultant alloy of Au and Ag has a higher tensile strength than pure Au. Another reason that a pure base material structure may show reduced strength is that covalent and/or ionic bonding between atoms of the same element is limited. Since alloys contain a mixture of atom sizes, and a variety of valence electrons because some of the atoms in the alloy's structure can have slightly different sizes and/or different localized electrical properties, it is more difficult for layers in the base material arrangement, such as base material layers 208, 218, and 228, to shift with respect to one another, as the arrangement of atoms is no longer uniform and the localized bond strength between neighboring atoms may be increased. This increase in strength of the alloy may be due to the slight difference in size of a substitutional solute, the inclusion of an interstitional solute, and/or other reasons.
Strengthening Mechanisms in Metals
As seen with respect to the descriptions accompanying
Dislocations may introduce different attraction and/or repulsion forces, known as stress fields, within an alloy structure. This creates a localized differential between forces within the alloy structure, known as a “pinning point,” that opposes motion of one or more base material layers of the structure proximate that pinning point.
Increasing the number of dislocations per unit of volume of the alloy structure will normally increase the tensile strength and/or yield strength of an alloy versus its base material structure in pure form. However, above a certain point, which may be different for each base material, an increased density of dislocations will begin to lower the tensile strength and/or yield strength of the alloy. If the localized differential of attractive and/or repulsive forces becomes widespread enough, it can reduce and/or eliminate any contribution of attraction and/or repulsive forces of the base material from the overall strength determination for the alloy, or it can cause the alloy structure to change form to a different underlying arrangement of the atoms in the alloy structure (e.g., from fcc to bcc, etc.).
As such, increasing the dislocation density, to a point, increases the shearing force needed to move one base material layer with respect to another. This is so because additional shearing force would be required to move the dislocations that lie within the layer(s) as well as the force needed to move the base material in those base material layers. This increase in shearing force needed to move the dislocations is exhibited as an increase in tensile strength and/or yield strength in the alloy.
However, increasing the strength of a base material may decrease other properties that the base material exhibits when the base material is in a pure form. For example, and not by way of limitation, increasing the strength may decrease the malleability of that base material. It may be known that stronger materials are harder to bend or dent. The malleability and/or elongation abilities of a material is often referred to as the “ductility” of the material. Changing how strong a material is, i.e., the ability of the material to resist force, often also changes how “workable” the material is, i.e., the ability to absorb force through deformation of the material rather than breakage of the material. Although many of the discussions herein refer to strengthening a material, in an aspect of the present disclosure, the strength of a given alloy can be improved without causing a significant effect on the ductility of the alloy.
Work Hardening
A typical structure of a pure base material may be a regular, nearly defect-free lattice. To harden a material through “work hardening,” dislocations are introduced into the base material through forming or otherwise “working” the material. These dislocations can create localized fluctuations of the stress fields in the material, which slightly rearranges the structure of the base material.
Work hardening of a base material may be achieved by applying mechanical and/or thermal stresses to the base material. For example, a sheet of Cu may be hammered, stretched, or run through pressurized rollers to reduce the material thickness. These mechanical stresses introduce dislocations into the Cu structure (which is face centered cubic). This forming of Cu increases the hardness (strength) and decreases the elasticity (commonly referred to as the “ductility”). Similar hardening can be achieved through thermal cycling, e.g., heating and cooling of the material, such as is done with furnaces and quenching of iron to “temper” the material.
As described herein, if “working” a base material continues beyond a certain point, the base material will contain too large a concentration of dislocations which may result in fractures, such as micro-fractures and/or visible fractures. Such fractures may be reversible, e.g., through one or more heating and cooling cycles of the material during and/or after working of the base material. Heating and cooling of the material in such a manner may be referred to as “annealing” the base material.
Work hardening may be performed on a base material without introducing a substitutional and/or interstitial solute to form an alloy. Work hardening may also be performed on alloys that include solutes with a base material.
Solid Solution Strengthening
In an aspect of the present disclosure, a substitutional and/or interstitial solute may be added to a base material, which can result in substitutional and/or interstitial point defects in the alloy structure. The solute atoms can cause lattice distortions in the alloy structure that impede dislocation motion. When dislocation motion is impeded, the strength of the material is increased. This particular mechanism of strengthening a base material may be referred to as “solid solution strengthening.”
In solid solution strengthening, the presence of solute atoms can introduce compressive or tensile stresses to the alloy structure lattice, which may interact with nearby dislocations, causing the solute atoms to act as potential barriers to the movement of layers of the structure with respect to each other. These interactions may increase the tensile strength and/or yield strength of a given alloy.
Solid solution strengthening generally depends on the concentration of the solute atoms present in the alloy structure. Some physical properties of substitutional and/or interstitial solute atoms that may be considered when determining which particular element to include in a given alloy may be the shear modulus of the solute atoms, the physical size of solute atoms, the number of valence electrons (also known as the “valency”) of solute atoms, and the symmetry of the solute stress field, as well as other properties.
Precipitation Hardening
As a molten metal alloy cools, the base material atoms may form molecules and/or bond directly with solute(s) (or other impurities) instead of forming bonds with other base material atoms. The molecules/bonds formed between the base material and solute(s) or impurities will likely create different localized properties than in the pure base material structure and/or pure solute(s) structure. One of these properties may be the melting point of the molecule, which may be different than that of the pure base material and/or pure solute(s).
In an aspect of the present disclosure, the molecules may harden at a higher temperature than the pure base material and/or pure solute(s), which may create dislocations in the alloy structure. These dislocations may create substructures within the alloy structure that may be referred to as a different “phase” of the alloy structure. Because molecules of different sizes within the alloy structure may make it more difficult for base material layers to move with respect to each other within the alloy structure, these molecules may assist in creation of a stronger alloy.
This change in properties of the molecules, which may be referred to as a change in “solid solubility” with respect to temperature, when it affects the strength of the resultant alloy, may be referred to as a “precipitation hardening” mechanism. Because the melting points of the elements included in the alloy may be different, precipitation hardening (also known as “precipitation strengthening”) may be dependent upon temperature.
Precipitation hardening uses these changes in solid solubility with respect to temperature to produce fine particles, e.g., molecules as described herein, of an impurity phase, or “second phase,” which impede the movement of dislocations. These particles that compose the second phase precipitates act as pinning points in a similar manner.
The particles may be of a similar size, or coherent size, as the base material. If the sizes of the particles and the base material are similar enough, the alloy structure can remain relatively coherent, e.g., can remain in a bcc or cubic form. However, in localized areas of the alloy structure, bowing and/or depressions may exist in the base material layers. This mechanism may be referred to as “coherency hardening” of the alloy structure, which is similar to solid solution hardening.
Where the particles have a different response to shear stress than the base material, this difference may change the tension and or internal stresses within the alloy structure. This response to shear stress is known as the “shear modulus” and because the particles can withstand a different amount of stress, the overall amount of stress that the alloy structure can withstand can be increased. This mechanism of precipitation hardening may be referred to as “modulus hardening” of the alloy structure.
Other types of precipitation hardening may be chemical strengthening and/or order strengthening, which are changes in the surface energy and/or an ordered structure of the particles within the alloy structure, respectively. Any one or more of these mechanisms may be present as a part of precipitation hardening in an alloy in an aspect of the present disclosure.
Dispersion Strengthening
Similar to precipitation hardening, changes in properties of the molecules, scattering different particles, molecules, and/or solutes within an alloy structure that are of different sizes than the base material may create dislocations within the alloy structure. Although these particles may be larger than those used for precipitation hardening, the mechanism of reducing the ability of base material layers from moving with respect to each other is similar. This mechanism may be referred to as “dispersion strengthening” to differentiate it from precipitation hardening. One type of dispersion strengthening is the introduction of an oxide of a base material in the alloy structure.
Grain Boundary Strengthening
In an aspect of the present disclosure, a unit cell of the alloy structure, e.g., one cube of an fcc, bcc, or cubic structure, etc., may be referred to as a “grain” or “crystallite” within the alloy structure. Solutes may affect the alloy structure by changing the average grain size within the alloy structure. When grains within the alloy structure have different sizes, the interface between adjacent grains, known as the “grain boundary,” acts as a dislocation within the alloy structure. Grain boundaries act as borders for dislocation movement, and any dislocation within a grain affects how stresses build up or are relaxed in adjacent grains.
Such a mechanism may be referred to as “grain boundary strengthening” of a base material in an alloy. In an aspect of the present disclosure, grains within the alloy structure may have different crystallographic orientations, e.g., bcc, fcc, cubic, etc. These differing orientations and sizes create grain boundaries within the alloy structure. When the alloy structure is subjected to external stress, slip motion between base material layers may take place. However, the grain boundaries act as an impediment to slip motion between base material layers because the base material layers do not have uniform, even surfaces where slip motion can occur.
Transformation Strengthening
As described herein with respect to precipitation hardening, a base material may cool into different “phases” depending on the rate of cooling, the temperature of cooling, and/or other factors. For example, titanium (Ti) may form two different types of grains, known as α-titanium and β-titanium. α-titanium is formed when the molten titanium metal crystallizes at low temperatures, and forms a hcp lattice structure. β-titanium forms when the molten titanium crystallizes at higher temperatures, and forms a bcc lattice structure. These different structures within an overall alloy structure create a stronger alloy, because the base material layers' smooth interfaces with each other are interrupted by the change in grain size and lattice structure of the different phases of the base material and/or solute(s). This mechanism for strengthening alloys is known as “transformation strengthening.”
In an aspect of the present disclosure, transformed phases of various base materials and/or solutes may occur as a function of heating and/or cooling the resultant alloy during formation of the alloy, e.g., heating the alloy to a certain temperature, cooling the alloy at a certain rate, heat treatment, etc. In an aspect of the present disclosure, during the 3D printing process of a given alloy, the temperature of the energy beam source 103 (e.g., the amount of energy being delivered by energy beam source 103), the speed that the energy beam travels across the powder bed 121 (e.g., the speed of deflector 105), and/or other factors may be selected to supply a desired temperature profile to the powder bed 121. For example, and not by way of limitation, the heating and/or cooling of a given powder 117 may be selected to approximate a heating and/or cooling profile to create desired phases of the base materials and/or solutes in the resultant alloy, and a different heating and/or cooling of a different powder 117 may be selected to create a different temperature profile to create desired phases in that powder 117's resultant alloy. In an aspect of the present disclosure, the temperature profile(s) delivered by PBF system 100 may also take into account any post-printing heat treatments, such that the combined printing/heat treatments may be performed in a more efficient manner.
In iron (Fe) structures, high levels of carbon (C) and manganese (Mn) solutes create two different grains within the alloy structure; ferrite, which is a bcc lattice structure, and martensite, which is a body-centered tetragonal (bct) lattice structure. These differing lattices within a Fe-based alloy structure strengthen the Fe into steel, because adjacent ferrite and martensite lattice structures disrupt the planar continuity of the base material layer interfaces, and the solutes (C and Mn) act as interstitional solutes to further disrupt the base material layer planes. Depending on how the alloy is heat treated, other lattice structures of Fe, e.g., austenite (which has an fcc lattice structure), bainite (which has a slightly different sized bct lattice structure than martensite), cementite (orthorhombic Fe3C), and/or other compounds, may also be formed.
A form of transformation strengthening, such as the creation of cementite in a Fe-based alloy structure, may also be referred to as “triferrite particle formation” within the alloy structure. Of course, if the base material is titanium, such transformation strengthening may be referred to as “tri-titanium particle formation; if the base material is aluminum (Al), such transformation strengthening may be referred to as “trialuminide particle formation,” etc. There also may be other forms of particles formed, such as a base material with two interstitial solutes or between interstitial and substitutional solutes, which may have a “di-” prefix, e.g., titanium diboride where both titanium and boron are used as solutes, etc., without departing from the scope of the present disclosure. Any number of different compounds, described with chemical prefixes, suffixes, and numerical monikers, comprising, consisting essentially of, and/or consisting base material(s) and/or solute(s) may be created within an alloy without departing from the scope of the present disclosure.
Alloy Compositions
In an aspect of the present disclosure, one or more base materials may be used to create an alloy. For example, and not by way of limitation, aluminum (Al) may be used as the base material; however, Al may be mixed with other materials, such as nickel (Ni), copper (Cu), titanium (Ti), iron (Fe), cobalt (Co), molybdenum (Mo), magnesium (Mg), chromium (Cr), and/or other materials, e.g., high entropy alloy (HEA) materials, etc., can be used by themselves as the base material. Other single base materials may also be substituted for Al without departing from the scope of the present disclosure.
One or more alloys of the present disclosure are configured with a balance of Al. In some aspects, the balance may include at most 0.1% by weight of trace elements. The Al may be alloyed with a set of other materials, such as one or more elements. Example elements that may be used to form Al alloys in some configurations may include magnesium (Mg), manganese (Mn), silicon (Si), chromium (Cr), titanium (Ti), zirconium (Zr), Yttrium (Y), and/or some combination of all or subset of the foregoing set of elements.
In some configurations, one or more alloys of the present disclosure may be a composition that may be mixed to include a balance of Al and the following materials: (1) Mg that is approximately 1-5% by weight of the composition; (2) Si that is approximately 1-3% by weight of the composition; (3) Co that is 0.2-1% by weight of the composition. In some configurations, the balance of Al may include up to 0.1% of trace elements.
In some other configurations, one or more alloys of the present disclosure may be the aforementioned composition of Al, Mg, Si, and Co, and the composition may include at least one of the following other materials:Ni, Ti, Zn, Zr, and/or Mn. When an alloy of the present disclosure is a composition that includes Ni, Ni may be 1-5% by weight of the composition. When an alloy of the present disclosure is a composition that includes Ti, Ti may be 0.05-0.5% by weight of the composition. When an alloy of the present disclosure is a composition that includes Zn, Zn may be 0.1-2% by weight of the composition. When an alloy of the present disclosure is a composition that includes Zr, Zr may be 0.05-0.5% by weight of the composition. When an alloy of the present disclosure is a composition that includes Mn, Mn may be 0.2-1% by weight of the composition. In various configurations, the one or more alloys of the present disclosure may include all, none, or some of the other materials Ni, Ti, Zn, Zr, and/or Mn.
An exemplary alloy of the present disclosure may include the elements in the amounts as shown in Table 1.
The example alloy may include specific amounts of Co, Ti, Si, Mg, Zn, Zr, Mn, and the balance of Al. Example I of Table 2 shows an example configuration.
The example alloy (Example I) may be processed with the L-PBF method to print test bars. The tensile properties obtained are shown in Table 3.
By way of illustration, the properties of AA 4046 in an as-printed condition may be given by Table 4, which illustrates a set of properties obtained from a set of tests of as-printed AA 4046 (note the last row illustrates the average value of the property across the set of tests).
The aluminum alloy may be formed into a powder, wire, or rod, e.g., for use in AM. AM raw materials may be manufactured by powder making processes as well as other methods, such as ingot metallurgy (FM) in which a solid ingot is manufactured by melting the metal along with added alloying elements and solidifying in a mold (e.g., ingot). The molded solid or ingot is then deformed by various wrought material production methods, such as rolling, extrusion, drawing, etc. The ingots, wires, and rods are either melted and atomized to make powders or fed directly into the laser, electron, plasma beams, or electrical arc, such as TIG, MIG, to melt the metal layer by layer for the manufacture of AM products.
Powder characteristics may be important for successful fusion within an AM machine such as PBF and/or DMD. Some aspects of alloy powders that may be advantageous for use with AM may include but are not limited to, good flow, close packing of particles and spherical particle shape. These aspects may lead to consistent and predictable layers.
The remainder of the disclosure is divided into sections. Each section has a set of figures that are labeled independently of figures in other sections. A brief description of the figures in each section appears at the beginning of the section. It is noted that there are multiple figures in different sections that have the same figure number. Likewise, there are multiple elements in different figures that have the same element number. However, the figures and elements each section should be considered only with respect to their section, therefore the figures and elements are described accurately with no ambiguity. It is noted that in some sections, the numbering of the figures does not start with the number 1, and in some sections, the numbering of the figures skips some numbers. However, regardless of the numbering scheme of the figures, the corresponding text of the disclosure matches appropriately to the figures.
The sections below describe various embodiments in which the alloys described above may be implemented. One skilled in the art will readily understand how various structures described below may be formed in various ways from the alloys. For example, various structures may be 3D printed with the alloys, extruded with the alloys, forged with the alloys, and may or may not undergo various post-processing such as heat treatment, shot peening, machining, etc. Any structure described herein may be formed of one or more of the alloys described above. For example, nodes, vehicle chassis parts, suspension structures, frames, load-bearing structures, non-load bearing structures, panels, tubes, etc. may be formed of one or more of the alloys.
The alloy may be produced with a 3D printing process that includes a cooling rate greater than 1000 degrees Celsius per second, and may be at least one of Laser-Powder Bed Fusion, Electron Beam Powder Bed Fusion, or Directed Energy Deposition.
Although the alloy may consist essentially of the magnesium, the manganese, the silicon, and the aluminum, such an alloy may optionally further comprise at least one of iron, titanium, zirconium, chromium, and yttrium. Such an alloy may also have a yield strength of at least 230 MPa, and may have a yield strength of at least 260 MPa. Any of the herein-mentioned alloys in aspects of the present disclosure may include aluminum in a range between 85 percent by weight of the alloy and 95 percent by weight of the alloy.
According to a first example, one configuration of the composition may include the balance of Al, the aforementioned percentages by weight of Mg, Mn, and Si, and may further include up to approximately 0.25% by weight of the Fe. In another configuration, the composition of the first example may include at least approximately 0.05% by weight of the Fe.
Iron is the most common impurity found in aluminum. Iron has a high solubility in molten aluminum, and is therefore easily dissolved at all molten stages of production. The solubility of iron in the solid state is very low and, depending on the cooling rate, it can precipitate by forming FeAl3, and more complex AlFeMgSi, in the alloy to provide additional strength if controlled in the disclosed level in the composition.
In some exemplary applications, the one or more alloys of the present disclosure may be used for AM in automotive engineering. For example, the one or more alloys described herein may be additively manufactured for the production of nodes, joints, and/or other structures, which may be applied in vehicles (e.g., cars, trucks, etc.). For example, the one or more alloys described herein may be additively manufactured to produce all or a portion of a chassis, frame, body, etc. of a vehicle.
The characteristics of the one or more alloys described herein may contribute to the crashworthiness of structures produced from the one or more alloys described herein. Moreover, the one or more alloys of the present disclosure may be configured with the materials (e.g., elements) described herein so that products additively manufactured using at least a portion of the one or more alloys may reduce the weight of vehicles at a suitable insertion point (e.g., in comparison with existing approaches to vehicle manufacture).
The one or more alloys of the present disclosure may feature characteristics and/or properties that exceed the corresponding characteristics and/or properties of various existing alloys, e.g., in the context of AM applications. An example alloy of the present disclosure may be processed with the L-PBF method to print test bars. Tensile properties may be obtained from the example alloy.
AM raw materials can be manufactured by powder making processes as well as other methods such as Ingot Metallurgy (FM) in which a solid ingot is manufactured by melting the metal along with added alloying elements and solidifying in a mold such as ingot. The molded solid or the ingot is then deformed by various wrought material production methods such as rolling, extrusion, drawing etc. The ingots, wires and rods are either melted and atomized to make powders or fed directly into the laser, electron, plasma beams, or electrical arc such as TIG, MIG, to melt the metal layer by layer manufacture AM products.
Powder characteristics may be important for successful fusion within an AM machine such as PBF and/or DED. Some aspects of alloy powders that may be advantageous for use with AM may include but are not limited to, good flow, close packing of particles and spherical particle shape. These aspects may lead to consistent and predictable layers.
The sections below describe various embodiments in which the alloys described herein may be implemented. One of ordinary skill in the art will readily understand how various structures described below may be formed in various ways from the alloys. For example, various structures may be 3D printed with the alloys, extruded with the alloys, forged with the alloys, and may or may not undergo various post-processing such as heat treatment, shot peening, machining, etc. Any structure described herein, as well as other structures, may be formed of one or more of the alloys described herein. For example, nodes, vehicle chassis parts, suspension structures, frames, load-bearing structures, non-load bearing structures, panels, tubes, etc. may be formed of one or more of the alloys of the present disclosure.
Blade supercar chassis 300 includes carbon fiber tubes 301 connected by one or more nodes 303. Each node 303 can include, for example, a central body and one or more ports that extend from the central body. In various embodiments, a multi-port node may be provided to connect tubes, such as carbon fiber tubes 301, to form a two or three-dimensional structure. The structure may be a frame, for example. In one example, a structure having tubes with axes in substantially the same plane can be referred to as a planar frame, while a structure having tubes with axes in different planes may be referred to as a space frame. A space frame may define a volume. In some examples, a three-dimensional space frame structure may be a vehicle chassis.
The vehicle chassis may be have a length, width, and height that define a space, such as a passenger compartment of the vehicle.
A vehicle chassis may form the framework of a vehicle. A vehicle chassis may provide the structure for placement of body panels of a vehicle, such as door panels, roof panels, floor panels, or any other panels forming the vehicle enclosure.
Furthermore the chassis may be the structural support for the wheels, drive train, engine block, electrical components, heating and cooling systems, seats, storage space, etc. A vehicle may be a passenger vehicle, a cargo vehicle, etc. Examples of vehicles may include, but are not limited to sedans, trucks, buses, vans, minivans, station wagons, RVs, trailers, tractors, go-carts, automobiles, trains, or motorcycles, boats, spacecraft, or airplanes (e.g., winged aircraft, rotorcraft, gliders, lighter-than-air aerial vehicles). The vehicles may be land-based vehicles, aerial vehicles, water-based vehicles, or space-based vehicles. Any description herein of any type of vehicle or vehicle chassis may apply to any other type of vehicle or vehicle chassis.
The vehicle chassis may provide a form factor that matches the form factor of the type of vehicle. Depending on the type of vehicle, the vehicle chassis may have varying configurations. The vehicle chassis may have varying levels of complexity. In some instances, a three-dimensional space frame may be provided that may provide an outer framework for the vehicle. The outer framework may be configured to accept body panels to form a three-dimensional enclosure. In some cases, inner supports or components may be provided. The inner supports or components can be connected to the space frame through connection to the one or more joint members of the space frame. Different layouts of multi-port nodes and connecting tubes may be provided to accommodate different vehicle chassis configurations. In some cases, a set of nodes can be arranged to form a single unique chassis design. In some cases, at least a subset of the set of nodes can be used to form multiple chassis designs. In some cases at least a subset of nodes in a set of nodes can be assembled into a first chassis design and then disassembled and reused to form a second chassis design. The first chassis design and the second chassis design can be the same or they can be different.
In this example, carbon fiber tubes 301 are carbon fiber material. In various implementations, other composite materials may be used. In various configurations, alloys such as the alloys described herein can be used. Examples of composite materials include high modulus carbon fiber composite, high strength carbon fiber composite, plain weave carbon fiber composite, harness satin weave carbon composite, low modulus carbon fiber composite, low strength carbon fiber composite, etc. In some implementations, the tubes may be formed from other materials, such as plastics, polymers, metals, metal alloys, etc. The tubes may be formed from rigid materials. The tubes may be formed of one or more metal and/or non-metal materials.
The connecting tubes may have different cross-sectional shapes. For example, the connecting tubes may have a substantially circular shape, square shape, oval shape, hexagonal shape, or an irregular shape. The connecting tube cross-section could be a closed cross-section. The connecting tube cross-section could be an open cross-section, such as a C-channel, an I-beam, an angle, etc.
The tubes may be hollow tubes. A hollow portion may be provided along the entire length of the tube. For example, the connecting tubes may have an inner surface and an outer surface. An inner diameter for the tube may correspond to an inner surface of the connecting tube. An outer diameter of the tube may correspond to an outer diameter of the connecting tube. A connecting tube may have two ends. The two ends may be opposing one another. In some embodiments, the connecting tubes may have three, four, five, six or more ends.
Various aspects of node-to-tube connections presented in this disclosure may be suitable for use in a vehicle chassis frame such as Blade supercar chassis 300 shown in
A node may be composed of a metallic material (e.g. an alloy described herein etc.), a composite material (e.g. carbon fiber, etc.), a polymeric material (e.g. plastic, etc.), a combination of these materials and/or other materials, etc. The node can be formed from a powder material. The nodes may be formed of one or more metal and/or non-metal materials. The 3-D printer can melt and/or sinter at least a portion of the powder material to form the node. The node may be formed of a substantially rigid material.
Nodes can be used, for example, as part of the chassis structures. A node is any 3-D printed part that is used to combine two or more parts together, such as tubes, extrusions, panels, or other nodes. The node may be used to provide support against different loads. A node may be found, for example, at the joint in a chassis framework. Further, in addition to connecting parts, nodes may be used for other purposes, including, for example, as crash structures. Using the principles herein, nodes can be manufactured using thin outer walls and selectively designed internal ribs for supporting the outer walls.
Chassis structure 401 includes internal ribs that contact an inner surface of walls 403 at rib edge lines 402, 404, and 408. In other words, rib edge lines 402, 404 and 408 show the edges of the internal ribs where the internal ribs meet the inner surface of respective walls 403. The internal ribs can be attached to an inner surface of walls 403 during the 3-D printing process, for example. The internal ribs that correspond to rib edge lines like 402, 404 and 408 can extend the full length across hollow portion 416 of the chassis structure 401, that is, the internal ribs can extend from one wall to an opposing wall on the other side of the chassis structure, as shown in more detail in
As shown in greater detail below, the ribs can include multiple sets of ribs. Here, each of rib edge lines 402, 404 and 408 belongs to a different set of generally parallel ribs. That is, in this embodiment, each set of ribs includes multiple, parallel ribs, such that each rib in a set intersects with one or more ribs in the other sets. In this way, for example, the intersections of the ribs can provide support to help allow the individual ribs to be self-supporting, and in some embodiments to help the intersecting ribs act as more effective stiffening structures when handling external loads on the chassis structure when the chassis structure is in operation. In other embodiments, additional or different criteria may be used to assist the ribs to be self-supporting as well as to allow the ribs to optimally handle external loads and attenuate high frequency plate modes. For example, placing the intersecting sets of ribs at different angles relative to one another may be another factor helping the ribs to be self-supporting, and/or helping the ribs to act as more effective stiffening structures when handling external loads. Print orientation 415 is shown to illustrate how the chassis structure and rib edge lines in
As is evident from
Referring back to
Producing a plurality of ribs in the third set (i.e., each rib-3508) can be used to further support the first and second sets of ribs (i.e. ribs-1502 and ribs-2504). This added support can enable chassis structure 401 to use only self-supporting ribs to act as stiffening structures that meet dynamic stiffness requirements while concurrently minimizing the mass of the chassis structure 401. Chassis structure 401 is for illustrative purposes only, and other chassis structures, such as other nodes, may use fewer or more ribs in each set of ribs, as necessary, to accomplish its target goals. In addition, while three sets of ribs are shown in
One advantage of the chassis structure 401 is that each of the ribs in all three sets is self-supporting. Further, in various embodiments, each of the ribs can be used as stiffening structures for attenuating high plate nodes, without any rib in the chassis structure 401 being used solely for supporting a wall during 3-D printing. Further, because the ribs may be used also to support the walls 403 during 3-D printing concurrent with their use as stiffening structures when in operation, the use of the self-supporting ribs effectively eliminates the need for external support structures, e.g., to support the walls 403 during 3-D printing. Another advantage of the chassis structure 401 in
In an aspect, at least one retention element 610 including a secondary connection 702 (see
In an aspect, the at least one retention element 610 including a secondary connection 702. The secondary connection 702 including a first adhesive 704 configured to secure the first AM part 602 and the second part 604. The secondary connection may be located to provide a connection between the first AM part 602 and the second part 604.
The example structure 600 may include a first additively manufactured (AM) part 602 and at least one retention element 604. The first AM part 602 may be a node, a subcomponent of a node, or other type of component. The AM part 602 may be printed through any conventional means including, for example, via PBF. The PBF printing may be performed using any technology suitable for use in PBF printing. These technologies may include, for example, selective laser melting (SLM), selective laser sintering (SLS), selective heat sintering (SHS), electron beam melting (EBM), direct metal laser sintering (DMLS), and others. In other embodiments, the AM part 602 may be printing using a different 3-D print technology such as fused deposition modeling (FDM). FDM AM may be ideal for printing various plastics, thermoplastics, etc. In general, the AM part 602 may be additively manufactured using any known AM technique or techniques.
One advantage of the use of AM in combining parts is that, due to the design flexibility of AM, the AM part 602 may include various features 612, 614, 616 that may, in turn, be used in conjunction with the adhesive-based part retention. For example, AM may be used to generate features 612, 614 that are adhered together, features 616 that carry adhesive to a location or locations (e.g., primary connection 606 and/or retention element 610, feature 614) where the AM part 602 may be adhered to another part 604, or a combination of both of these (e.g., features 612, 614, 616). Furthermore, adhesive-based part retention may be combined with mechanical-based part retention. For example, primary adhesive-based part retention may be combined with mechanical-based part retention. Secondary adhesive-based part retention (e.g., holding parts together while a primary adhesive is applied, dries, and/or cures) may be combined with mechanical-based part retention. Some combination of primary adhesive-based part retention and secondary adhesive-based part retention may be combined with mechanical-based part retention. Mechanical-based part retention may include, for example, groove that retains a snap-ring, screw and shim, spring-loaded clips, clips, a snap-like part retention element, snap-like part retention feature slidably engaging with a receptacle on an another part, a Christmas tree fastener, magnets, a tongue and groove connection, or other mechanical-based connections.
In an example, the first AM part 602 may be configured to connect to a second part 604. The second part 604 may include, for example, an AM part, a tube, a panel, an extrusion, any other type of conventionally-manufactured part, or a COTS part. Thus, structures formed may be manufactured by bonding together, for example, two (or more) AM parts (e.g., where one AM part may be considered the first AM part), or an AM part (e.g., where the AM part may be considered the first AM part) and a tube, panel, extrusion, or any other type of conventionally-manufactured part, or a COTS part.
The connection between the first AM part 602 and the second part may be via a primary connection. For example, the primary connection may include a primary adhesive for bonding the structures together. The primary connection may be applied to an interface between the first AM part 602 and the second part 604. For example, the primary adhesive may be applied.
A part retention feature (e.g., part retention element 610) may, in some embodiments, be temporary and may be removed after the primary adhesive bond between the structures is formed. Adhesive(s) may also be used for the part retention features. For example, at least one retention element may be included. The at least one retention element may include a secondary connection 702. The secondary connection 702 may include an adhesive configured to secure the first AM part 602 and the second part 604. Furthermore, the secondary connection 702 may be located to provide a connection between the first AM part 602 and the second part 604.
In an aspect, the first adhesive includes a hot melt material applied between a first mechanical feature 614 associated with the first AM part 602 and a second mechanical feature 612 associated with the second part 604. The hot melt material may include any form of hot melt adhesive, hot melt glue, or another thermoplastic adhesive. Generally, however, the hot melt adhesive, hot melt glue, or another thermoplastic adhesive may be quick curing such that hot melt adhesive, hot melt glue, or another thermoplastic adhesive. Accordingly, the hot melt material may be a quick curing adhesive or a quick curing sealant.
In an aspect, hot melt material may be used. The hot melt material may be a quick curing adhesive or sealant that may be applied to the mechanical features on two components to be connected. The features may have an increased surface area. The increased surface area may enable sufficient bond strength to retain the two (or more) parts being connected. Once the hot melt retention fluid cures, adhesive may be injected between the nodes being connected. The cured hot melt feature would ensure that the two parts 602, 604 are retained during the adhesive injection process. The retention force (i.e., the force provided by the hot melt holding the two nodes together) would be higher than the adhesive injection force, thereby securely holding the parts 602, 604 in the proper orientation and with the required separation distance to ensure repeatable bonds.
In an aspect, the first adhesive includes an ultraviolet (UV) cured adhesive applied between a first mechanical feature associated with the first AM part 602 and a second mechanical feature associated with the second part. UV cure systems 706 may be utilized as part retention features. In this embodiment, adhesives at the retention features would be UV cured such that they are held in place during the adhesive injection and curing process. The UV cure adhesives would be applied at strategic locations to provide sufficient retention force. The UV cure adhesive would be configured to cure prior to the adhesive injection and curing.
In an aspect, the primary connection 606 between the first AM part 602 and the second part 604 includes a second adhesive 708. For example, a secondary adhesive may be between the first AM part 602 and the second part 604 where the first AM part 602 and the second part 604 meet, e.g., as illustrated in
In an aspect, the first adhesive 704 is faster curing than the second adhesive 708. For example, as discussed herein, hot melt material such as, hot melt adhesive, hot melt glue, or another thermoplastic adhesive that may be quick curing may be used as the first adhesive 704. The second adhesive 708 may cure more slowly.
In an aspect, the secondary connection 702 further includes a mechanical structure (e.g., making up retention element 610). For example, the secondary connection may include both an adhesive and mechanical-based part retention. Mechanical-based part retention may include, for example, groove that retains a snap-ring, screw and shim, spring-loaded clips, clips, a snap-like part retention element, snap-like part retention feature slidably engaging with a receptacle on another part, a Christmas tree fastener, magnets, a tongue and groove connection, or other mechanical-based connections that may be used in addition to the adhesive.
In an aspect, the mechanical structure may be integrated with at least one of the first AM part 602 and the second part 604. For example, mechanical structure 618 may be integrated with the first AM part 602. Mechanical structure 620 may be integrated with the second part 604.
In an aspect, the mechanical structure is co-printed with at least one of the first AM part 602 and the second part 604. For example, mechanical structure 618 may be co-printed with the first AM part 602. Mechanical structure 620 may be co-printed with the second part 604.
In an aspect, the mechanical structure is separate from the first AM part 602 and the second part 604. For example, mechanical structure 618 may be attached to the first AM part 602 after the first AM part 602 is manufactured. Mechanical structure 620 may be attached to the second part 604 after the second part 604 is manufactured.
In an aspect, the at least one retention element 610 including a secondary connection 702. The secondary connection 702 including a first adhesive 704 configured to secure the first AM part 602 and the second part 604. The secondary connection may be located to provide a connection between the first AM part 602 and the second part 604.
As illustrated in
In an aspect, a means for additively manufacturing a first AM part 602 may include a 3-D printer system (e.g., PBF system) or another additively manufacturing system. The means for additively manufacturing a first AM part may manufacture the first AM part 602 configured to connect to a second part 604 via a primary connection 606 applied to an interface 608 between the first AM part 602 and the second part 604.
In an aspect, a means for attaching the second part 604 to the first AM part 602 may include a mechanical device or devices (such as one or more manufacturing robot) for attaching the second part 604 to the first AM part 602. For example, the manufacturing robot(s) may locate the second part 604 proximal to the first AM part 602.
In an aspect, one or more manufacturing robot(s) may apply one or more adhesives to one or more retention elements. Accordingly, in an aspect, a means for applying the first adhesive may include one or more manufacturing robot(s). For example, a dedicated robot (or robots) may be used to apply adhesive(s). In another example, the one or more manufacturing robot used for attaching the second part 604 to the first AM part 602 may also be configured to apply adhesive(s). Accordingly, the means for applying the first adhesive may include aspects of the for attaching the second part 604 to the first AM part 602 that apply the adhesive(s).
Manufacturing robot(s) may attach the second part 604 to the first AM part 602 using at least one retention element 610 including a secondary connection 702. The secondary connection 702 may include a first adhesive configured to secure the first AM part 602 and the second part 604. The secondary connection 702 may be located to provide a connection between the first AM part 602 and the second part 604.
A means for applying the first adhesive may be configured to apply the first adhesive during one of application of the second adhesive, during curing of the second adhesive, prior to application of the second adhesive, and/or prior to curing of the second adhesive. In an aspect, the adhesive(s) may be applied to secure the first AM part and the second part during application of the second adhesive. In an aspect, the adhesive(s) may be applied to secure the first AM part and the second part during curing of the second adhesive.
In an aspect of the disclosure, the additively manufactured core 1108 may include unique arrays of lattice structures and/or custom honeycomb structures.
Referring still to
The AM core material in general may take on any of a variety of conventional or organic shapes, or somewhere in between, depending on the most ideal structural optimization for the panel application at issue. Conventional core material may include, for example, foam cores, which may include open or closed cell, and which may provide generally homogenous support of the skins. Other conventional core material may provide more structured, non-homogenous support of the skins including textile cores for punctual support, cup-shaped cores for providing regional support to both skins, corrugated cores that provide unidirectional support and honeycomb cores, which provide bi-directional support. In addition to these and other conventional core patterns, any type of custom core pattern can be generated and used on its own, or combined with any one or more conventional patterns. The optimization of the panel can take into account a number of parameters and the structural patterns of support can differ as a function of position at any point on the panel. Thus, different load magnitudes and directions can be accommodated at each point on an operational panel in an optimal manner.
The face sheets 1102a-b may be additively manufactured, or in some embodiments, co-printed with the panel core. Alternatively, the face sheets 1102a-b may be manufactured using conventional methods. For example, the face sheets 1102a-b may be manufactured using a hand or automated composite layup, which includes laying dry fabric layers or prepreg plies onto a tool to form a laminate stack. The dry fiber laminate stack is infused with resin in a wet layup procedure, and the resulting materials are allowed to cure. Alternatively, a pre-preg laminate stack may be compacted after placement onto the tool and heated to allow curing. In an exemplary embodiment, the face sheets are produced using resin transfer molding (RTM). In RTM, a preform material may be placed into a mold, which is then closed. A specific resin mixture including a low viscosity resin for quick permeation and even distribution may be added to the mold via inlet ports. Vacuum may be used to facilitate the resin injection process. The part is then cured to produce one or both face sheets 1102a-b.
In other exemplary embodiments, the face sheets 1102a-b are produced using resin injection molding (RIM), vacuum assisted resin transfer molding (VARTM), resin film infusion (RFI), compression molding, injection molding, and the like.
Following assembly, the face sheets may be adhered to the additively manufactured core 1108 as described. In some alternative embodiments, the face sheets 1102a-b may be co-printed with the additively manufactured core 1108. In these embodiments, the face sheets 1102a-b may be adhered to the additively manufactured core 1108 via an adhesive after the AM process has concluded. Alternatively or in addition, the face sheets 1102a-b may be affixed to the additively manufactured core 1108 using another conventional method, such as via thermal fusion or the like. The face sheets and core may also be built as one continuous AM build. Alternatively, the panel components may be co-printed, with the joining of the components done by an alternative AM process, if assembled in a MAP or similar process. Thus, for example, the MAP can co-print the panel components and then join the components, e.g., by applying an adhesive. The joining of the components can also be performed using a separate procedure, e.g., if a MAP is not used.
While the face sheets 1102a-b of
In an alternative embodiment, face sheets 1102a-b may be connected to respective sides of the additively manufactured core 1108 during the AM process, as opposed to after the AM process.
The core 1108 may use different inputs. For example, the core 1108 may be additively manufactured as a honeycomb structure or another structure such as an optimized structure based on multiple inputs across physics models. The AM process, being non-design specific, may use instructions provided to a 3-D printer containing an optimized design of the additively manufactured core 1108 to meet the objectives of an intended structural application. For example, depending on the application of the panel 1108, such as for use in the flooring or as part of an interior side panel, etc., the optimization would enable the specification physical parameters (e.g., tensile strength, rigidity, thickness, force vectors including shear forces and vertical forces etc., pressures and gradients thereof, energy absorption characteristics by crush direction, etc.) and other potential geometrical, thermal, and material-based properties relevant to manufacturing the panel 1100 for the intended structural application. In another exemplary embodiment, the panel 1100 may be a section of a fuselage or vehicle exterior, in which case various aerodynamic characteristics may be optimized for that intended application by varying the shape of the face sheets in three dimensions. As described below, customizing the additively manufactured core for an application may simply involve describing the geometry of the desired structure in a data model.
In general, the instructions to the 3-D printer may provide a modified honeycomb structure (or other custom structure, e.g., lattice structure) that changes the properties of the panel to make it more suitable for a given application. This optimization process may conventionally be complex and involve substantial experimentation and design effort. However, according to certain aspects of the present disclosure, this potentially arduous process can be replaced wholesale, or at least substantially accelerated, using CAD or other software suites to form the core. The resulting data and instructions can be included as part of a data model representing the core along with the other parts, if any, to be additively manufactured. The optimized data model with the corresponding instructions can then be provided to the 3-D printer, which then renders the physical structure.
The CAD instructions and/or the data model of the structure can also be varied to produce corresponding variations of the honeycomb structure. One advantage at this point is that no tooling or other hardware is needed through this period; the design process can advantageously be replaced with algorithms for optimizing the panel itself, instead of the conventional time-consuming process involved in identifying or constructing expensive tooling to produce the core. More generally, what is conventionally accomplished using complex physical tooling and labor-intensive manpower, and in some cases inefficient trial and error methods, can now be accomplished in software and easily and efficiently converted to a hardware structure at a lower price using less labor.
The extensive versatility of 3-D printing also means that the designer is not limited to conventional honeycomb structures. Rather, in other exemplary embodiments, the core 1108 can be additively manufactured using any type of structure optimized for the intended application, as will be described with examples below. After the desired additively manufactured core 1108 is additively manufactured, a panel 1100 may be formed by adhering plates 1102a and 1102b to opposing sides. In an exemplary alternative embodiment, the entire sandwich panel (additively manufactured core and face sheets) may be additively manufactured together, potentially with other co-printed structures. That is to say, in an exemplary embodiment, these structures can be additively manufactured together with the face sheets (like the panel 1100 of
In addition, the printed or formed face sheets can in some embodiments vary in thickness at different locations, similar to the variable thickness of the core. Thus, some face sheets can both vary in thickness in contour. This enables a curved panel or panel with substantially any contour to be produced using the principles described herein.
Conventionally-produced honeycomb panels may result in anisotropic properties. Anisotropic properties are directionally dependent in that they vary in different directions. Different types of anisotropic properties may be important to panel design considerations in transport structures. Exemplary anisotropic properties differ per the material at issue and may include, for example, tensile strength, heat conduction, shearing forces, and other material-dependent properties. While anisotropic properties may be present in certain useful and high-quality materials such as, for example, carbon fiber composites, these properties are often an undesirable artifact for the applications of a custom honeycomb panel to which this disclosure is directed.
Additively manufacturing cores for sandwich panels, instead of using conventional manufacturing processes to fabricate the cores, can result in structurally optimized cores. Unlike traditional honeycomb panels, panels with additively manufactured core structures advantageously can offer quasi-isotropic properties, while maintaining the same or similar weight characteristics as conventionally manufactured honeycomb cores. Quasi-isotropic properties are those properties that are not directionally dependent in-plane. For example, a panel may exhibit quasi-isotropic features when the tensile stiffness and strength of the panel remain generally the same regardless of the direction in which the panel is pulled or otherwise subject to a tensile force in-plane.
The underbody configuration of
Regardless of whether ICE, EV, or hybrid propulsion systems are used, however, the parts that make up these systems, such as the electric motors, battery pack and the associated circuitry distributed within the vehicle can, in an embodiment, all be acquired as COTS parts. Accordingly, the use of the conventional platform obviates the need for the manufacturer to invest Capital Expenditures (CapEx) in tooling and machining equipment to assemble these structures from the ground up. Certain parts in
The vast majority of components illustrated in
A node (e.g.,
In some embodiments, nodes may have additional features and structures to effect a particular function. For example, some nodes may include unique geometries or material compositions for handling different load bearing regions of the vehicle. These geometries may include lattices, honeycombs, and other types of patterned structures. Nodes may also include one or more channels for routing adhesive, sealant or negative pressure (vacuum) to and from one location to another. In other embodiments, multiple nodes may be co-printed and positioned adjacent one another in a desired portion of the vehicle.
Nodes may route electronic circuitry or lubricants from one structure (e.g., a tube) to another, (e.g., a gear case). The flexibility of nodes to accomplish these functions derives in large part from the non-design specific nature of the 3-D printer upon which the current platform is based. For example, using a computer-aided-design (CAD) program, a custom representation of 3-D node can be generated and designed to include unique shapes, interfaces, and other details. The CAD model can then be sliced to provide software-based layers of the original 3-D structure. The sliced model and printing instructions can then be provided to the 3-D printer. In a powder bed fusion (PBF) printer, for example, the slices are successively deposited as layers of powder on a substrate in a print chamber. One or more lasers or other energy sources may selectively fuse each layer or slice based on the custom instructions to render the designed node.
Nodes may be non-definition nodes or definition nodes. A definition node is described in more detail below. A non-definition node is any node that is not a definition node. For example, referring to the ref. no. 1242 in
Referring back to
The complex structures illustrated in
AM is a valuable resource and its use is prioritized; thus, utilizing COTS parts means that any priority strain on the 3-D printer(s) can be effectively managed. In some embodiments, mass and material consumption of the AM parts can be minimized by including COTS parts with the design. COTS elements may also be inexpensive and readily available. COTS elements have typically known geometries with easily accessible specifications. Thus, wherever feasible, COTS elements may be ideal for incorporation in the manufacturing platform along with AM structures.
Use of COTS elements also eliminates the capital expenditures that would otherwise be required for the machinery and manpower to produce and assemble these structures in-house. The platform is predicated in part on the capability of the manufacturer to viably and timely produce a variety of models. Thus, acquiring COTS parts reduces the capital expenses that would be incurred for building the same parts in-house, rendering the COTS option generally desirable. In an embodiment, certain COTS parts can be acquired and modified to provide a custom design.
Additively manufacturing certain sections of the vehicle in accordance with the platform may enable modular construction and assembly of vehicles. Modular vehicles may be assembled by joining multiple discrete systems or components together to form one vehicle. Unlike conventional vehicles, modular vehicles provide the freedom of customizability. Complex parts and consoles can be removed easily, both for functional and aesthetic purposes, and new parts and consoles can be added in a straightforward manner. Because AM technologies are not tooling intensive, AM can be used to facilitate the development of modular systems by efficiently fabricating a variety of customized designs that maintain pace with customer requirements and demand.
AM also provides modular processes with the capability to define and build complex and efficient interfacing features that define partitions between modules. These features can include indentations, tongue and groove profiles, adhesives, nuts/bolts, and the like. A further advantage of implementing modular designs for use in vehicles is ease of repair. Modular designs ensure easy access to virtually any component in the vehicle. In the event of a crash, the affected modular block(s) can be replaced. The block(s) can also be co-printed with other blocks or structures to save assembly time. The blocks can further incorporate in-situ scanning and observation to ensure accurate joining and repair of the modules.
Using a modular design approach, the AM vehicle may be assembled as a collection of 3-D printed and non-printed components, including COTS components, integrated together via well-defined interconnection means for attaching the components at desired transitions. Individual components may be added and removed without requiring changes to other components in the vehicle. The use of the definition nodes as described below, in cooperation with the remaining non-definition nodes, enables the modularity of vehicles constructed using the platform.
In addition, modular design and assembly approaches make it possible for flexible manufacturing cells to be configured for assembly. Advantages include reduced reliance on fixtures during assembly (eventually complete elimination), lower assembly cell footprint in comparison to traditional assembly lines, etc.
In an embodiment, having identified the desired vehicle profile and optionally mapped out the basic design requirements, the manufacturer may further break down the vehicle design into sections. One reason for breaking down the vehicle model into sections is to enable the manufacturer to delineate the COTS parts or functions from the non-COTS parts or functions. Another reason for the breakdown is to understand how, if at all, the parts in each section will ultimately interface or interconnect with one another. With this knowledge, the manufacturer can produce and assemble definition nodes as described in greater detail herein.
In an embodiment, a number of vehicle sections may be equivalent to the number of wheels, although this need not be the case and other considerations may dictate that a greater or fewer number of sections are more suitable. In the case of a four-wheel vehicle, the manufacturer may elect to break into four (4), six (6) sections, for example. Each section may comprise one or more additively manufactured parts that can be configured to interface with COTS parts including, for example, suspension, wheels, electric motors, crash beams, pillars, and the chassis members. Accordingly, in this phase of the process, the manufacturer may consider and identify the different COTS structures that will likely reside in a section, and how these structures will be interconnected with which parts. Using this preliminary information, the manufacturer can further identify what functional and geometrical structures may be needed to accommodate each one of those interconnections in the relevant section.
In addition, the manufacturer may also need to consider other factors including anticipated temperatures/pressures in various parts of a section, estimated structural integrities and load-bearing capabilities in light of anticipated loads, crash regulations, material properties, weak and strong points in the vehicle design, and other factors. With this information, the manufacturer can identify an optimal structure, or collection of substructures, that can accommodate all of the necessary interconnections in light of the identified load and other requirements, for a section. The information obtained from this analysis can be used in the assembly of AM nodes for that section.
While the platform includes incorporating ICE architectures, which can be produced to the manufacturer's benefit using the principles described herein, ICE architectures tend to consume a significant portion of the vehicle's volume. As a result, ICE propulsion systems have historically been a constraint to automotive manufacturing. By contrast, integrating electric vehicle (EV) propulsion systems with AM structures dramatically reduces the CapEx and complexity of manufacturing automobiles. Unlike the internal combustion engines and systems that occupy a substantial portion of the front of the vehicle (and therefore place practical limitations on how the vehicle's space can be used), the electric motors may be placed immediately adjacent the AM nodes (below) that define the perimeter of the vehicle.
Further, as noted herein, the battery pack may be placed in the vehicle underbody or floor. The hood area of the car can be effectively cleared for other uses as a result. Like ICE engines, transmissions, etc., EV propulsion systems (such as batteries, motors, wiring) can be procured as COTS members and can simply be integrated with the AM structures and other adjacent COTS members as necessary. The AM structures in these cases can be fabricated in a manner that easily accommodates these EV components. For example, to match the geometry and interface of a particular EV COTS part, such as a set of protrusions used to connect to the vehicle, a corresponding AM structure can be printed with apertures perfectly aligned to receive the protrusions such that the parts can be easily integrated together. Incorporating EV propulsion systems into the platform consequently has significant benefits. Therefore, for embodiments using EV propulsion systems, the platform accords significant flexibility to the manufacturer in vehicle design by providing more usable volume. Further, parts can be acquired and assembled quickly, and the availability of AM with the ubiquitous nature of COTS parts means that propulsion systems need no longer be a significant constraint to vehicle manufacturing.
Definition nodes are so-called because they define the vehicle to be made. In an embodiment, the locations of the definition nodes may be determined by the internal volume requirements of the vehicle. For example, the definition nodes may be more closely spaced in a small hatchback car (owing to its small size), in comparison to a large sedan or SUV. In an SUV, by contrast, the nodes are farther away, both for nodes along a side of the vehicle and nodes on opposing sides. The definition nodes may be placed along the perimeter of the vehicle to enable the manufacturer to control the vehicle's internal volume. The platform's use of definition nodes advantageously removes the requirement of expensive tooling of vehicle parts to determine internal volume and the CapEx incurred with this former endeavor.
Once the locations are identified as described herein, the definition nodes may be additively manufactured and, using the information and analyses herein, the AM nodes may be uniquely configured to interface with COTS suspension components, electric motors, crash beams, side crash beams, pillars, and other panels or elements that define the chassis and the interior package volumes. The underbody (
In the embodiment of
Referring back to
Definition nodes 1401-1406, in practice, may incorporate a variety of functions, or distribute similar functions among different sections. In an exemplary embodiment, a definition node includes a plurality of additively manufactured substructures connected together. Each substructure may be dedicated to a specific interface or function. The definition nodes 1401 and 1402, for example, may route fluids and circuitry to and from other COTS or AM parts. The definition nodes may serve additional and different functions. For example, definition nodes may include lattice structures to maximize strength-to-weight ratios based, e.g., on the anticipated loads the six section vehicle is expected to sustain over a period of time. Definition nodes 1401-1406, or portions thereof, may also be geometrically shaped to provide further support to the paneling with which it interfaces and to withstand structural loads. A definition node in some embodiments may include two or more co-printed substructure nodes, each substructure node used to interface with the same or different elements depending on the desired configuration.
Any of the definition nodes 1401-1406 may be connected to the vehicle using different methods. In one embodiment, the 3-D printed nodes are attached to the underbody panel, or floor structure. The definition nodes (e.g., 1401, 1402, 1404, 1406) may also connect to the front and rear crash structures. The same four definition nodes may also be coupled to the suspension components, such as the control arms and struts. The definition nodes, as noted herein, also interface with many or most of the COTS parts that will reside in the particular section with which the definition node is associated.
As may be evident from the illustration of
While some embodiments of the platform may dictate that the design and positioning of the definition nodes be performed first, in other embodiments involving EV propulsion systems, the battery pack may be first assembled. In general, however, the design and preparation of the definition nodes is prioritized, because after these nodes are positioned and fixed, the majority of the remaining tasks tend to fall into place.
The panels and structures used to connect to the definition nodes generally need to be machined for precision. A significant advantage of the platform is that the machining tasks can be performed by the COTS supplier—not the vehicle manufacturer. Thus, the manufacturer may be spared from having to make significant capital expenses to fund the tooling required for these tasks.
In scenarios where hybrid/internal combustion engine (ICE) vehicles are to be manufactured, the internal volume requirements may factor in packaging volumes to accommodate the ICE, transmission, drive shaft, and other components that may be unique to, or more pronounced in, hybrid or ICE designs.
The illustrative examples of
The definition node(s) can include connection interfaces to connect to a plurality of parts. For example, the definition node itself may be broken down into multiple components and connected to each other. The definition nodes may be connected to the dash and floor panels utilizing node-to-panel connection features enabled by adhesives. The node may connect to the crash structures (front crush rail) using mechanical fasteners, which may include nuts, bolts, screws, clamps, or more sophisticated fastening mechanisms. The node may utilize adhesive connections, mechanical fasteners, or a combination of both to connect to extrusions. Additively manufacturing definition nodes can enable the platform to create optimized structures in either a single manufacturing operation not requiring any machining or requiring minimal machining operations upon completion of the printing.
Front crush rail 1620 is coupled to definition node 1633, as is front cargo tub 1624. In an embodiment, front crush rail 1620 is composed of extruded aluminum. Hood seal flange 1637 is a vertical flange that follows the top of the front cargo tub 1624. Strut tower 1635 is part of the definition node 1633 and interfaces with front cargo tub 1624 and hood seal flange 1635. Definition node 1633 further includes a node material reduction panel 1618, which may be a composite honeycomb sandwich panel. Dash panel 1614 is shown in cross-section and may also be a honeycomb sandwich panel.
Cowl/IP armature panel 1604 may interface with a vertical portion of the definition node 1633. Also shown is the front quarter node 1606, which in this embodiment is an integral part of, and co-printed with, definition node 1633. Adjacent front quarter node 1606 is door seal flange 1608. Toward the rear of the drawing is sill 1610, which may constitute extruded aluminum. Sill cladding 1612 is connected to sill 1610. Sill cladding can, in an embodiment, be constructed using low cost tooling.
The definition node 1633 of
In short, once the nodes are manufactured, COTS panels, extrusions, tubes, and other parts can logically be connected to form interfaces with the nodes. Node-based modular construction methods provide the ability to realize multi-material connections, which are paramount in meeting strength-to-weight metrics for automobiles and other complex transport structures. Furthermore, galvanic isolation may be provided between galvanically incompatible materials being connected by utilizing nodes to include isolators to space and prevent physical contact between the dissimilar materials.
The platform enables a common architecture for manufacturing a plurality of vehicles. The platform may include additively manufactured definition nodes, which may be assembled with EV/hybrid powertrain components, tubes, extrusions, panels, roof structures, and other components. Furthermore, this platform enables maximization of the available internal volume for occupants and cargo. By utilizing definition nodes and controlling their location, a vast product portfolio enabled by a single platform is possible. The platform also enables the creation of smaller footprint factories to manufacture an entire portfolio of vehicles, as noted herein. Since this platform relies on the marriage between additive manufacturing and COTS elements, with potentially limited (if any) use of conventional manufacturing techniques, it can enable the creation of distributed production units all over a geographic area of interest configured to run in parallel, that are not susceptible to the production halts prevalent in traditional vehicle assembly lines.
It should be noted that the four vehicles shown are a very small representation of the different possible vehicular configurations that can be implemented using the current platform. The manufacturer is no longer limited to producing a single model due to limitations inherent in the conventional assembly-line approach. In other embodiments, large vans and multi-person transports can be assembled using the platform as described herein. In still other embodiments, by positioning the definition nodes accordingly, vehicles can be made very wide, very narrow, long, short, high, low, or somewhere in between any or all of these parameters.
At the border region 1924 of cast component 1902 are connection features 1908 and 1910. In an exemplary embodiment, connection features 1908 and 1910 are part of cast component 1902 and are cast or machined together with the rest of the component 1902. In other embodiments, connection features 1908 and 1910 may be parts of other components, including, for example, Interface Nodes. In this former embodiment wherein the features 1908 and 1910 are included within the component 1902, connection features 1908 and 1910 may be made of the same material (e.g., aluminum, plastic, etc.) and in this event they are subject to the same thermal constraints as that material. This fact may be taken into consideration in determining whether connection features 1908 and 1910 can be used in an environment containing significant amounts of thermal energy. In general, whether or not the connection features 1908, 1910 are part of the cast component 1902, they may be connected to other components, including standard AM joints, other AM Interface Nodes, etc. Connection features 1908 and 1910 are negative features because they include respective grooves 1930a and 1930b. Thus, connection features 1908 and 1910 in this embodiment are configured to engage with complementary features that use positive connection features. These prospective engagements with connection features 1908 and 1910 are shown by respective arrows 1920 and 1922.
Interface Node 1906 may be connected to cast component 1902 via the tongue connection at groove 1932 (as noted) together with the surface regions of component 1902 adjacent groove 1932 that contacts Interface Node 1906. The negative connection feature including groove 1932 may be engaged with the complementary, positive connection feature of Interface Node 1906 via an appropriate adhesive. In this exemplary embodiment, precision fluid ports with fluid channels 1916 (only one shown) may be built into Interface Node 1906 to supply an adhesive and on an opposing side, to provide negative pressure in order to promote distribution and spread the adhesive. Interface Node 1906 may also provide sealant grooves 1914a and 1914b or similar structures to provide a sealant to facilitate proper distribution of the adhesive. In addition, spacers or other structures (not shown) may be incorporated into the connection feature on the Interface Node 1906 to prevent galvanic corrosion when certain dissimilar materials are involved. In another embodiment, channel 1916 may instead be part of a network of cooling channels in Interface Node 1906 for delivering fluid to and from the cast component 1902 to carry thermal energy away. Additionally, Interface Node 1906 may itself be composed of a material configured to dissipate thermal heat from cast component 1902. In this case, Interface Node 1906 may be made of a material with a significantly high melting point to accommodate the direct connection to cast component 1902.
In this example, Interface Node 1906 removes complexities from the cast component 1902. Interface Node 1906 incorporates the complex thermal features that otherwise would be necessary for integration into at least a region of cast component 1902. This saves manufacturers from having to make changes to the cast or to add the necessary complexity to whatever conventional technique is used, tasks which would otherwise increase lead times and lower throughput. Interface Node 1906 also incorporates the complex fluid ports 1916 and other potential structures in order to ensure a secure a proper seal to cast component 1902, thereby reducing or eliminating the need for cast component 1902 to embody these features.
Interface Node 1906 also includes on the other end an additional negative connection feature 1912, which may constitute any node-based connection. For example, connection feature 1912 may be configured to connect the node 1906 to any suitable structure. For example, node 1906 may be connected to connecting tubes, panels, and other structures. In addition, the structure comprised of node 1906 and component 1902 may be one of two or more, or a network of, similar structures which may all be connected together through connection features similar to connection feature 1912.
The Interface Node 1906 illustrated in
In addition, the connection feature 1912 on the Interface Node and the connection feature defined by groove 1932 on the cast component need not be a tongue and groove structure, and other connection features may be equally suitable. For example, the connection feature 1912 may in an alternative embodiment include a pair of tube-like protrusions having an inner and an outer diameter, the smaller protrusion inside the larger protrusion, for enabling a connection to carbon fiber connecting tubes, thereby coupling the connecting tubes to the cast component 1902 via Interface Node 1906. More generally, on the end of the Interface Node where connection feature 1912 currently resides, features may be incorporated to enable connection to any other component, including for example, extrusions, other nodes, other castings, etc. In an embodiment, a plurality of node-casting interfaces as described herein may be used to form a chassis for a transport structure. In this embodiment, the type of component 1902 may vary from region to region of the vehicle, and may not be used wherever not needed. In other embodiments, a single Interface Node may include a plurality of interfaces 1912 for multiple connections.
In turn, Interface Node 2006 may be printed using one of the higher throughput PBF techniques, or generally any appropriate high precision AM technique whether or not identified in this disclosure. In this example, the size of the interface 2013 is the same size that would normally be used for a transport structure with comparable engine and transmission parts, for example. That is, the interface 2013 would not be reduced in size, unlike potentially other portions of Interface Node away from interface 2013. Interface Node 2006 also includes interfaces 2022a-b and high-precision threaded interface 2024, which may be connection features for connecting to other Interface Nodes, Linking Nodes, which in turn, may connect to other components (e.g., drivetrain, transmission, etc.). In appropriate embodiments, Linking Nodes may be used.
In an embodiment, the Interface Node 2006 includes a network of reinforcing structures 2015 used to securely affix the interface 2013 to the remaining connection features 2022a-b, 2024. The network of reinforcing structures 2015 and connection features 2022a-b and 2024 may in some embodiments be substantially reduced in size to accommodate a high volume production with respect to the manufacture of Interface Nodes 2006. The geometry of the network of reinforcing structures 2015 would be determined by topology optimization, and these geometries would leverage the capabilities of additive manufacturing to fabricate complex structures which would otherwise be difficult or impossible to fabricate using conventional manufacturing processes. In this example, other Interface Nodes or structures that may connect to Interface Node 2006 via one or more of the connection features 2022a-b and 2024 may also be reduced accordingly. In an embodiment, reductions may be made in any area of the Interface Node outside of the interface that do not physically affect the function of the components in a negative way.
In some configurations, it may be desirable to provide isolation between the conventionally manufactured component and the Interface Node in the event that the materials are dissimilar. Isolation may assist in preventing galvanic corrosion that may otherwise occur due to the difference in the electrode potentials of the materials used for each structure. Accordingly, an exemplary embodiment may include a structure for achieving the required spacing.
In contrast to bolting, Interface Node 2106B is configured to be bonded with Linking Node 2113 via a double-shear (node-node) connection. More specifically, Interface Node includes at its base an area (
Interface Nodes 2106A-B respectively include contours 2144A-B that are well streamlined to receive and support spanning components such as tube 2116, while demarcating a physical size for the Interface Nodes 2106A-B that is not larger than necessary. Thus, these Interface Nodes 2106A-B are designed to be compact and feature rich, and only of a size that is necessary to accommodate the functions performed by their high precision features, as further shown in
Linking Node 2113 may include elongated sections 2150 of a reinforcing metal material, and other shapes that may be designed to enable a strong bond and a proper load transfer across the body of connected elements. Linking Node 2113 may be produced by a fast, albeit generally lower precision, AM process such as DED. As a result, different metals, such as any of the alloys described herein, may be used in the manufacturing process such that Linking Node 2113 can inherently include load-bearing strength and also, due to its material strength, may be a reliable connector of the Interface Nodes 2160A-B.
Referring to
As noted, the adhesive inlet port 2110 and vacuum port 2112 are easily seen in this view. An important aspect of this view is the texture 2132 defining the filling between structures 2114 and the interior of 2170 adhesive that was circularly distributed throughout the interior by the action of the adhesive inlet and the vacuum. The adhesive 2132 is shown flowing to the bottom of the surface. For example, 2132a defines regions where the adhesive has saturated both sides of the circular flange and is sealed from further migration by O-rings 2108 and 2109. In this way, the adhesive forms a very strong bond between the flange 2104 of the Interface Node 2106B and an interior portion A of node 2106B configured to fit, with room to spare for adhesive, around the flange 2104.
At the top of
As shown in the embodiment of
While two Interface Nodes are shown for the purposes of this example, more than two nodes or other ports may be used in other embodiments.
Interface Node 2188A further includes 3-D printed connection features 2197 which in this exemplary embodiment includes a cylindrical protrusion with high precision threads for connecting to Linking Node 2186. Because Linking Nodes may include lower precision features but are typically enable of including high precision features such as very fine threads for mating with connection feature 2197, a “captive nut” 2193 is shown embedded in the Linking Node 2186. The nut 2193 may be a 3-D printed or a standard off the shelf part. In an embodiment, the Linking Node 2186 is 3-D printed with the captive nut 2193 placed inside. Proper supports are printed around the captive nut 2193 while the linking nut 2186 is printing. The connection features 2197 of Interface Node 2188A can thereupon be inserted into the captive nut 2193 and thus the Interface Node 2188A can be tightly bonded together with Linking Node 2186. In another embodiment, captive nut may be co-printed with the Linking Node for a suitable printer.
Additionally,
In another embodiment, prior to the application and curing of the adhesive, the isolation feature 2195 may be inserted between the node Linking Node 2186 and the component 2190 to provide a space between the Linking Node 2186 and cast component 2190 such that physical contact between the two parts is avoided, thereby avoiding subsequent problems with galvanic corrosion if the metals are dissimilar. In addition, in some embodiments, sealants and other features such as standoffs for fixturing may be incorporated into Linking Node 2186 and/or component 2190 for use in the spacing and isolating procedures. All of these steps may advantageously aid in the prevention of galvanic corrosion where different materials having different respective electrode potentials are used in the substructure (node and component) of the structure.
In some embodiments, an Interface Node may be 3-D printed using a unique asymmetrical shape rendered by the 3-D printer to accommodate a specific space inside a transport structure or other mechanical device.
In an embodiment as noted herein, the techniques in
These procedures are in contrast to conventional reliance solely on traditional manufacturing techniques which are more often than not characterized by significant tooling and machining costs, and needless additional lead time. Moreover, the use of conventional procedures would in many cases render it impossible to fabricate a chassis which most closely matches the ideal structure for optimal load path distribution. Conversely, the Interface and Linking Nodes benefit from the non-design specific feature of additive manufacturing by enabling the precise realization of the load paths and related chassis features.
As another exemplary application, transport structures utilize crash components manufactured using traditional processes (stamping, extrusions, etc.). In lieu of these conventional procedures, the Interface Node-based infrastructure can be used to implement complex connection-based geometries that correspond to an optimal load path. Rather than investing significant time and money in machining these components to correspond to the desired optimized topology, the components can instead be procured using relatively simple geometries through any high-volume conventional means or high volume printing means. The components can thereupon be connected via Interface Nodes for implementing the most suitable and optimal load path to address crash performance.
The principles and techniques herein further provide a manufacturer with capability to produce simple parts using conventional processes and nodes incorporating part complexity using AM processes. In the example of cast parts as described herein, casting is a tooling intensive manufacturing process. Additionally, as described herein, it is difficult to fabricate cast parts with complex features such as mechanical reinforcements, cooling channels and the like. Using AM Interface Nodes, complex features can be developed on or within the node instead, which enables the designer to preserve relative simplicity of the conventionally manufactured feature.
In another embodiment, AM Interface Nodes can be used to augment mechanical reinforcement in regions bearing high loads. Accordingly, if the cast part and Interface Node are designated to be placed in a region which may be subject to significant gravitational loading and other forces, the Interface Nodes may be rendered to provide additional support to counteract this loading in addition to the cast part.
In the example of
The AM Interface Node 2206 may connect over an open end of the bell housing 2210. The Interface Node 2206 surrounds the end of the bell housing 2210 and covers the end portion with fingerlike members 2215. The Interface Node 2206 includes a standard size interface 2214 for connecting to engine block 2220 a plurality of threaded bolts 2225, at least in part, for connection features to the bell housing 2210 and engine block 2220. In this embodiment, the bolts extend into visible channels that surround the engine block 2220 interface. In other embodiments, the Interface Node 2206 may be coupled to component 2220 via, for example, a tongue and groove connection, bonding, welding, or other suitable connection feature.
Interface Node 2206 may also be fabricated with features designed to dissipate the heat. For example, Interface Node 2206 may be constructed with complex networks of cooling channels. In this embodiment, the fingerlike members 2215 that extend from and surround the perimeter of the end of bell housing 2210 may assist in transferring heat from node body 2206 accumulated as a result of the connection to a heat source (engine block 2220) and to dissipate the heat. The temperature gradient may be made more manageable due to the members 2215 as the increased surface area provides improved heat transfer characteristics in comparison to flush contact by the node 2206 with the heat source without members 2215.
In other implementations, Interface Node 2206 may incorporate other sophisticated features to support processes such as welding, mechanical fastening, adhesive bonding, and the like, to secure a connection both to the Interface Node 2206 and to an engine block 2220 interface or other channel to which it will be ultimately affixed.
In an exemplary embodiment, complex or high precision features that are traditionally used on or associated with the component may be instead incorporated into the Interface Nodes. These high precision features may include geometrical and structural complexities such as various connection features for coupling the components with the Interface Nodes.
More generally, these high precision features may include, by way of example, intricate shapes, substructures, or patterns disposed on or integrated within a part, multiple regions of curvature or other complex shapes designed to perform one or more functions, singly or in concert with other elements. Examples include structures traditionally used with machines, motors, or other mechanized equipment and mechanized assemblies; specialized parts such as features in custom panels; materials or combinations of materials organized into specific shapes to perform predetermined functions; repetitive patterns such as networks of links, rods, rails, fingers, or other intentionally designed arrays of substructures; small or microscopic structures and features integrated onto or within the part; and finely tuned materials organized in a coherent or meaningful way to perform a designated function. Geometrically complex features may also include structural updates, upgrades, enhancements, or features that require changes from part to part and include, for example, features or substructures whose design or shape changes from part to part. Such features or structures may present throughput difficulties in a casting or molding application because, for example, different sets of tooling shells may be required to provide the needed changes on each part. Structurally high precision features may also include electronic circuits and elements such as inductors, coils, and capacitors. Such features may also encompass integrated circuits, processors, electronic devices, physical input features (such as one or more switches), user interfaces, displays, and the like.
These high precision features may further include mounted fixtures, specialized flanges, vertically and horizontally threaded mounting plates, floating nuts, clamps, screws, and other fixtures that include extra detail or especially fine geometries that may be distributed across the structure and that by design may require careful positioning. While components and Linking Nodes may include flanges, plates, screws and other features, generally the Interface Node provides such structures with greater sophistication, smaller sizes, specialized or custom substructures, and unique, design dependent features. In addition, the Interface Node may provide the structures in a compact way with tight 3-D spatial margins, such as the Interface Node in
High precision features may also include substructures whose geometries accommodate or enable intended rotating or translating motion either integrated within the structure or provided externally, or both. Common features may be high precision, as is generally evident to one of ordinary skill in the art, in situations where they require precision placement or where they are integrated into a more complex array of additional types of structures. For example, high precision features may demand strict tolerance requirements, such as involving parts that must be oriented relative to one another with precisely defined angles or distances. Parts may also need to be positioned relative to one another at precise ranges or distances in order to function properly. These parts may need to be manufactured using separate machining techniques or precision AM technologies.
Commonly, features may be high precision in cases where a part containing the feature cannot practically be manufactured with an acceptably high throughput (relative to the application) using the same manufacturing process used to produce the remainder of the part. For example, while a vehicle gear case may be fabricated using a traditional casting technique, internal channels for providing adhesive or negative pressure to specifically defined regions of the cast part may have to be separately constructed using another method in order to achieve the desired throughput for the finished gear case.
Examples of high-precision features may also include structures having specific material requirements. For example, certain regions of the structure may be composed of a specific type of material or combination of different materials. Different regions of the structure may require use of different materials depending on the geometry of the structure, the load characteristics of the structure and adjacent structures, and other considerations pertinent to the application for which the structure is being used.
High precision features involving material properties that may compromise throughput may include one or more of rigidity, elasticity, ductility, malleability, hardness, thermal tolerance, resistance to corrosion or contaminants, mass, physical stability, or chemical reactivity or resistance thereto. The level of precision of various features may also include the extent and manner in which the features require specific thermal characteristics, including different melting points, thermal control over phase changes, required heat capacities, etc.
Unlike conventional processes which use sheet metal construction metallic braze tubes to sheet and affix headers, additively manufacturing the header 2302 with the divider 2307 allows for fluid-tight division between the header sections 2308 and 2310. Advantageously, this can allow dissimilar fluids to flow in the header sections 2308 and 2310. Structures allowing fluids to be closely brought together in the same structure can have reduced mass, and hence realize improved heat transfer effectiveness Eff.
The microtube array 2303 has a plurality of microtubes separated into a first microtube array 2312 and a second microtube array 2316. Microtubes from the first microtube array 2312 can carry a first liquid or fluid, and microtubes from the second microtube array 2316 can carry a second liquid or fluid. For instance, microtubes including microtube 2314 can carry a liquid such as oil, and microtubes including microtube 2318 can carry a liquid such as a water-based coolant, although numerous other fluids are possible depending on the application.
As described herein, an AM microtube heat exchanger can be used to manufacture the header 2302 so that it is integrated with the microtube array 2303. This can be accomplished without traditional brazing techniques, and the header 2302 can be configured as a fluid distribution manifold for fluids.
The AM microtube heat exchanger can cool the fluids flowing within the microtubes of microtube array 2302 by exchanging heat to air flowing perpendicular, or substantially perpendicular, to the microtubes. For instance, as shown in
Although the AM microtube heat exchanger 2300 shows a header having two header sections 2308, 2310 and first and second microtube arrays 2312, 2316, other configurations are possible. For instance, an AM microtube heat exchanger can be manufactured with a header having greater or fewer than two header sections; and more or fewer microtube arrays can be separated for carrying different types of liquids. Also, by using a 3D manufacturing process, the header 2302 can have internal chambers (not shown) with any desirable high performance shape. For instance, the header 2302 can be formed in the shape of a triangle or to have triangular features.
The header 2302 can be additively manufactured from a base plate (not shown) at the interface 2305. In this way the header 2302 can be additively manufactured with the microtube array 2303 to be continuous.
Microtubes can be arranged as a planar web connecting a separation distance between tubes arranged parallel to the flow path of liquids flowing inside. This can advantageously allow support material to connect to a row, referred to as a datum row, to provide support during the additive manufacturing process.
In some embodiments microtubes can be manufactured so that the microtube or tube axis is substantially parallel to the force due to gravity; in other embodiments microtubes can be manufactured so that a microtube or tube axis is substantially normal to the force due to gravity. When manufactured with a tube axis normal to the gravitational force, microtubes can be arranged so that they are secured or tied back to a datum (single supporting) row. When manufactured with a tube axis parallel to the gravitational force, microtubes can be free-standing.
In other embodiments rows and columns can be positioned using simple linear vectors allowing for a simplified analysis and design procedure. Configurations of rows and columns that provide an integral support structure can also be lighter than those that need additional material when constructed largely normal to the gravity vector. Also, hollow beam elements can be fluid passages, and appropriately designed unit cells can propagate and transport fluid across spans. Advantageously, additively manufacturing a header, such as the header 2302 of
Advantageously, 3D printing allows for superior compact manufacturing of microtube arrays by creating an integrated seal. The integrated seal allows for the creation of an AM microtube array 2500 having less mass than one created by traditional brazing techniques. This in turn can allow for improved heat exchanger effectiveness Eff and improved surface transfer area.
As described herein, heat exchanger effectiveness Eff can be a figure of merit for analyzing and designing a microtube heat exchanger. Effectiveness Eff, which is the generally accepted figure of merit for a heat exchanger, can also be defined as the fraction of minimum temperature difference of fluid outlet over fluid inlet.
In a two fluid heat exchanger such as a gas and liquid system where the liquid flows through a microtube array (hot fluid) exchanging heat to the gas (the cold fluid), a simplified analysis based on concepts of energy balance give Equation 1, below. Equation 1 relates the heat transfer effectiveness Eff in terms of temperatures of the hot and cold fluids measured at heat exchanger inlet/outlet ports. In Equation 1 the port temperatures are as follows: Tcold,out, the temperature of the cold fluid flowing out of the cold fluid outlet (port), Tcold,in, the temperature of the cold fluid flowing into the cold fluid input inlet (port), Thot,out, the temperature of the hot fluid flowing out of the hot fluid outlet (port), and Thot,in, the temperature of the hot fluid flowing into the hot fluid input inlet (port). As expressed in Equation 1, the heat transfer effectiveness Eff is a dimensionless figure of merit, and temperature can have dimensions of degrees (deg C.).
E_ff=(T_(cold,out)−T_(cold,in))/((T_(hot,in)−T_(cold,in)) Eq. 1
In addition to Equation 1, a graphical procedure may be required to analyze a heat exchanger as a function of additional parameters including, but not limited to, the microtube length L as shown in
Extrusions 2706 may be used to span areas on the vehicle incorporating simple, straight, constant sections of material. In an embodiment, the extrusions 2706 are 3-D printed. More generally, any of the parts or components that are non-printed may, in other embodiments, be 3-D printed. In addition, dash & windshield frame module 2708 is disclosed. A modular dash & windshield frame module 2708 may ideally identify a single piece dash and windshield aperture for providing optimal structural performance, dimensional accuracy and design flexibility. Thus, in this example, module 2708 may be treated and installed as a single, complex module incorporating the identified dash and frame.
B-Pillar module 2710 may include, for example, a single piece printed box section incorporating a large section of hardware characteristic of that portion of vehicle 2700. For example, B-Pillar module 2710 may include hinges, striker, seat belt mounts, and other equipment associated with the side portion of the frame and the front passenger seat. Rear Floor module 2712 may incorporate printed ‘X’ members and rear suspension mounts. Similarly, C-Pillar & Rear Quarter module 2714 may embody features similar to B-Pillar module 2706 but for the rear right portion of vehicle 2700 adjacent the wheelhouse. Back light aperture 2718 may frame the back-light and complete the roof structure. For hatchbacks and vans, this feature may become the tailgate aperture, which may incorporate hinges and strikers. It will be appreciated that vehicle 2700 may be partitioned in different ways depending on the ease of integration, dependence of module features on other features, the characteristics and build plate size of the 3-D printer involved in the AM process, and preferences of the programmer.
Because Main Floor module 2716 in this example represents a large planar array area, module 2716 may include, for example, composite honeycomb shear panels which in many embodiments are used for such large planar areas. It should also be noted that, depending on the size of the 3-D printer and corresponding build plate, the exoskeleton-based frame in one exemplary embodiment may be printed in a single rendering. Alternatively, like the other components, the frame may be printed as a series of modules, particularly if the size of the build plate and AM geometry is smaller than the array defined by module 2716.
Exoskeleton vehicles are those whose exterior surfaces provide the needed structure. The exoskeleton is designed to sustain the majority of operational and structural loads on the vehicle and to protect the passengers during a response to an impact event. Like a conventional frame, an exoskeleton frame may include cavities for accommodating an external interface (namely, cavities and other sections for fitting windows and other systems including headlights, HVAC systems, and the like). As described further below, the exoskeleton frame may include custom honeycomb panels or similar reinforcing structures for providing support in the event of an impact. In these embodiments, the vehicle frame rails can be eliminated.
The use of exoskeleton frames also provides the capability to modify the materials in specific areas of the frame to provide further support. For example, to protect occupants in the event of a frontal impact, internal support material within the frame can be made softer to absorb energy. Plastic materials that are 3-D printed using FDM may be used for this purpose.
To meet pedestrian impact requirements and to protect a pedestrian in an impact event, the exoskeleton frame can be composed of structures made to be thinner, weaker, or out of different materials (e.g., plastic) in the relevant regions of the vehicle. For example, the hood, or portions thereof, can be structurally designed to be thinner or weaker, and can be made of plastic parts to enable it to deform upon impact. In regions away from the pedestrian protection zone, these characteristics may be unnecessary and the frame can consequently be made stronger.
In an embodiment, a section of the panel can be made to deform or crush in a vertical direction or other direction maximizing pedestrian protection, wherein that same section can be made much stronger in a longitudinal direction. Composites having directional strength properties, such as carbon fiber, may be suitable for this purpose.
Additionally, while printing exoskeleton based transports, free spaces can be printed that include matrix arrays filled with lattices. This configuration provides both structural support and weight savings.
Referring back to
Further, another advantage as indicated herein of this strong skin disposed about the periphery of the transport is that the wheelbase distance 2804 (
In one exemplary embodiment of
With reference again to
As discussed herein, the exoskeleton frame may be designed to deform or give way when impacted. For example, in an impact on the hood from above, the internal lattice structure may be configured to collapse. Conversely, when struck in a longitudinal direction in a forward vehicle impact, the frame may be designed to absorb the energy and maintain its structural integrity.
It should also be noted that, while the honeycomb or lattice structure sandwiched between the two layers provides additional reinforcing support without imposing dramatic increases in mass, in some embodiments the honeycomb structure may be omitted in certain regions. That is, honeycomb/lattice supporting structure can in some cases be omitted from certain regions of the vehicle in specific embodiments.
The benefits of using AM in the context of the examples herein include the absence of any need for custom tooling or a factory footprint. AM makes it possible to print multiple types of vehicles or transports using a single 3-D printer. Ideally, the particular 3-D printer chosen would only need a sufficient printing resolution to enable printing of Class-A surfaces directly without the need for post-printing operations. AM technologies with high resolutions make it possible to print parts with extremely complex geometries, yet with smooth surfaces on the Class-A side.
Subject to the possible exceptions herein, in the vehicle embodiments directed to the exoskeleton structure, the main structure of the vehicle is additively manufactured in the form of honeycomb panels over substantially the entire surface of the transport. These panels in turn handle the road loads associated with driving as well as the impact loads from a collision.
In another exemplary embodiment, the walls of the transport are carefully and methodically arranged to incorporate more efficient structure (e.g., structures having lighter weight and using fewer materials) where it is needed and conversely, to incorporate strength in other areas where strength is paramount.
The frame 3100 of
In another aspect of the disclosure, the AM model of the exoskeleton frame includes a plurality of cavities and apertures for housing components that require a vehicular external interface. These components may be a subset of the overall group of components that are an integral part of the transport and assembled and integrated into the transport. These components may also be configured to be modular as discussed herein, such that damage to one of the components does not reflect a need to repair or replace unrelated component. In one embodiment of exoskeleton-based transports, the rear surface of the vehicle and greenhouse may be exposed. One advantage of using AM to manufacturer such structures is to leverage the flexibility of design and geometry afforded by AM. Panels may thereupon be installed, as part of the AM process or otherwise. Glass may be installed in the greenhouse cavities.
Interior door panels and similar structures in this embodiment would be configured to fit the cavities or sections of the exoskeleton that were 3-D printed. Such cavities can have strategic locations for easy access. Instrument panels, HVAC units, lighting modules and other components for integration can be 3-D printed as well, after which they can be plugged into the matching sections as a straightforward insertion of a known component in an accessible position. As noted herein, one principal advantage of this assembly technique is that it may facilitate straightforward repairs and replacements of modules and systems requiring service.
This procedure is in stark contrast to the challenges of subsystem management present in conventional systems, in which facilitating access to specific subsystems for purposes of installation or repair may not be straightforward. One example of a classic shortcoming in transport structures relates to lighting systems. Conventional transports include instruments and lighting that may be designated to fit into the transport with little, if any, regard to ease of access, meaning for example that other subsystems may present obstacles to the installation, or that the frame is not simply not amenable for easy integration with lighting and other components. The problem may be exacerbated if the various instruments having different functions are combined with one another and/or have unique or difficult external connections.
Oftentimes the sheer amount of time to remove and replace instruments subject to these undesirable locations, painstakingly complex wiring profiles, and other obstacles, is so economically inefficient that practitioners opt instead to replace a much larger portion of adjacent working components to enable an easier repair. In contrast to this not uncommon scenario, AM provides adaptability. That is, by designing an architecture that provides easy access to almost every component in the vehicle, reparability becomes easier and less expensive. Automated transports having a modular layout facilitate easy, almost seamless reparability as compared with conventional vehicles.
Another exemplary embodiment involving AM exoskeleton structures is to specify the model design of a portion of the structure such that the exoskeleton is on the outside and the panel inlays are on the inside. The exoskeleton is sealed in this manner. Significant weight savings may be achieved as exterior panels in this embodiment are eliminated. These transports may have excellent crash absorbing abilities because appropriate crash-absorbing features with ideal geometries may be 3-D printed on the outside of the transport. Such results are incredibly difficult to achieve using conventional manufacturing techniques.
In another exemplary embodiment, the entire structure can be 3-D printed with interior features based on the model of the 3-D exoskeleton, as before. This time, however, the entire structure can be 3-D printed to accept panels. In one embodiment, the panels can be printed as an integrated structure with the frame. The printed panel sections could resemble Voronoi patterns or other patterned features. An example of a Voronoi pattern 3300 is shown in
It should be noted in
In other embodiments, the 3-D printing of the frame, the construction of the mobile transports for moving parts, people and robots to and from the various assembly cells, and the construction of modular components is performed by automated constructors armed with instructions to build the vehicle seamlessly.
The present disclosure addresses key obstacles and provides solutions for a various shortcomings in the art. One such obstacle includes the viability of additively manufacturing a vehicle frame and the limitations on the current sizes of available built plates and 3-D platform geometries for printing. One of multiple solutions to this problem is to include the frame itself as one of the modular subsystems and to reconnect the frame into one cohesive unit after multiple renderings of the individual segments of the frame. The modular design may present easier reparability options for the consumer. As build plates and printer profiles evolve to match or exceed the size of such transports, the manufacturer has the option to decide to maintain modularity of the frame. In some embodiments, the frame can be printed in a single rendering with built in indentations or connections to maintain modularity.
The node 3505 and the interconnect 3510 are co-printed, or additively manufactured together during the same printing process. For instance, the interconnect 3510 and the node 3505 may be designed in a Computer Aided Design (CAD) file that is transferred to a 3-D printing device. The 3-D printer may then process the file and initiate a print process based on the file. The node/interconnect structure may then be printed during the same print process.
During the printing process, support structure 3530 may also be co-printed to hold the interconnect 3510 and node 3505 together in the socket 3515. Support structure 3530 may comprise thin spokes and/or protrusions that are configured to break apart so that the interconnect 3510 is then free to move around in a rotational and/or linear manner depending on the configuration of the socket 3515. The support structure 3530 may also be used to confine the movement of the interconnect 3510. For instance, protrusions may be used to confine the angular rotation of the interconnect 3510 to be within a specific range.
As shown, the head 3540 may be spherical in shape. Additionally, the head 3540 is arranged with the socket 3515 to form a joint. The joint may be a rotating or linear joint. The interconnect 3510 is configured to connect the node 3510 to a component. In some embodiments of the apparatus, the component may be a tube such as the tube 3535. The shaft 3545 may be configured to slide into an end portion of the tube 3535. In some embodiments of the apparatus 3500, the distal end of the interconnect 3510 may have an end cap that is configured to slide over an end portion of the tube. An end cap may be a component that has a cylindrical shape like a tube with a slightly larger diameter that is designed to fit over a tube. Although the tube is cylindrical in this example, one having ordinary skill in the art will appreciate that a number of different shapes may be utilized for the tube and/or end cap arrangement such as a multisided polygon, without departing from the scope of the disclosure.
Additively manufacturing parts provides the ability to utilize techniques that are not available in traditional manufacturing processes that typically weld parts and/or components together. For instance, complex structures like the adhesive port 3525 may be printed in the node 3505. The adhesive portion 3525 may include a channel that extends from an exterior surface of the node to the socket 3530. The adhesive port 3525 is configured to inject an adhesive material into the joint formed by the socket 3515 and head 3540. The adhesive material may be injected when the head 3540 is positioned in such a manner that enables the shaft 3545 to slide into the tube 3535. In some embodiments of the apparatus 3500, the shaft 3545 may be inside of the tube 3535 prior to adhesion injections. In some embodiments of the apparatus, the adhesive material may be a polymer such as an epoxy, resin, or any material that forms a strong bond between the interconnect 3510 and the node 3505. In some embodiments of the apparatus, and as will be discussed with respect to
One of ordinary skill in the art will appreciate that the node/interconnect structure described with respect to
For instance,
In some embodiments of the apparatus, a mixture that forms an adhesive material may be applied. For instance,
As discussed herein, additively manufacturing parts provides the capability of printing nodes and/or interconnects in a variety of different shapes. This provides greater customizability to meet a variety of needs when manufacturing a complex mechanical product. Such customizability reduces cost and manufacturing time.
As shown, the distal end 3935 of the interconnect 3905 has an end cap configured to slide over an end portion of the tube 3915. The proximal end 3940 of the node 3905 has a dovetail shape. The proximal end 3940 fits into the dovetail shaped socket, such as the socket 3920. The socket 3920 and the proximal end 3940, together, form a dovetail joint.
As discussed with respect to
Optionally, the apparatus 3900 may also include an injection port and/or vacuum port, as described herein to apply an adhesive to fix the interconnect 3910 in place. The adhesion process may be used in addition to or in lieu of swaging the node 3905.
By additively manufacturing parts, a variety of different shapes and configurations can be realized that were not possible with traditional manufacturing techniques for complex mechanical structures. The dovetail joint is one example of a configuration that can be generated by additively manufacturing a node and interconnect.
In some embodiments of the apparatus, the socket 4030 is substantially cylindrical. The interconnect 4010 includes a shaft 4070 that is connected to an interior surface 4065 of the socket 4030 opposite an opening 4060 of the socket 4030. In some embodiments of the apparatus, the interconnect is a mandrel. Additionally, the interconnect includes head 4055 at the proximal end as well as a distal end 4050. As shown, the head 4055 is extendable beyond the opening of the socket 4030. As described herein, the socket 4030 includes a section 4025 with an outward bulge around a portion of the interconnect shaft 4070.
As shown, an end portion of the tube 4020 is positioned over the interconnect 4010. The end portion of the tube 4020 also includes a section 4025 that has an outward bulge around the shaft 4070 of the interconnect 4010.
The injected material 4015 may be a polymer such as silicone or a hydraulic fluid. As shown, the material 4015 is applied in between the end portion of the tube 4020 and the interior surface 4065 of the socket 4030 and the head 4055 of the interconnect 4010.
In some embodiments of the apparatus, a hydroforming process is utilized to cause the tube 4020 to deform. For the hydroforming process, the material 4015 is a hydroforming material such as silicone that is injected in the tube 4020 after the tube 4020 is inserted in the socket 4030. The injected material in combination with the interconnect 4010 generates pressure within the tube 4020. The pressure causes the tube 4020 to deform by bulging along the portion 4025 of the socket 4030 that has the outward bulge. This deformity forms a mechanical seal between the tube 4020 and the node 4005. At the culmination of the hydroforming process, the material is expelled from the socket 4030 and the tube 4020 is connected to the node 4005.
In some embodiments of the apparatus, more than one node may be utilized to connect a component such as a tube.
As shown, the interconnect 4110 is configured to connect the first and second nodes 4105 to the tube 4115. In some embodiments of the apparatus, the interconnect 4110 comprises an end cap having one or more slides 4130 configured to slide into an end portion of the tube 4115. For instance, the slides 4130 may comprise several semicircular slides configured to slide into an end portion of the tube 4115.
The first and second nodes 4105 may be arranged with the end cap to form a slot through which the tube 4115 slides through to attach the end portion of the tube 4115 to the end cap.
The left-most node 4105 includes the injection port 4120, which includes a channel extending from an exterior surface of the node to the slot for adhesive injection. The node 4105 also includes the vacuum port 4125, which includes a second channel extending from the exterior surface of one of the nodes 4105 to the slot. The injection port 4120 and the vacuum port 4125 cooperatively work to inject and pull the adhesive material 4135 through the slot to hold the slot and tube in place. In some embodiments of the apparatus the vacuum port may enable at least a partial vacuum environment through the slot. Screw threads 4140, in conjunction with threaded screws, may alternatively be used to hold the slides 4115 in place instead of the adhesive material 4135.
Another example of 3-D co-printing includes printing the housing for the electric motor with the control arm. Co-printing these components can enable the design of superior propulsion systems for vehicles, which are only possible through AM. The electric motor can also be mounted on the center of mass of the control arm, as shown with reference to
In another exemplary embodiment, interface centers can be provided at predetermined regions of the vehicle while being manufactured. These regions can serve as joints between two or more sections of the vehicle that fail during a crash. The repairs on the vehicle are effected simply by removing the damaged section and 3-D printing a new one with the remaining part of the vehicle. This approach is in contrast to the conventional approach where not only the damaged structure is replaced, but the surrounding parts as well. This novel approach also makes recycling of damaged parts much easier.
Interior structural components can be produced through AM using modular techniques. For example,
Instrument panels and firewalls constitute some of the most complex areas of a vehicle. Typical dash structures have numerous parts and require complex fixturing. Using AM and modular designs, the dash can be optimized to reduce total part count and lower fixturing needs. Moreover, AM can enable lightweight yet durable materials to be 3-D printed, which may result in significant cost savings. Among other advantages, this approach can create significant opportunities for OEMs to increase production of diverse dash assemblies and to enable the OEM to produce multiple variations of the assemblies while reducing capital expenditure.
In an aspect of the disclosure, a 3-D printed mega dash is disclosed. The 3-D printed mega-dash according to an exemplary embodiment may replace numerous individual stampings such as the dash, upper and lower cowl, strut towers, upper load path beams, and cowl sides. A pillar lowers outers, hinges, reinforcements and brackets. Further, the 3-D printed mega dash concept can easily be implemented into a traditional Body-in-White (BIW) build strategy.
Currently, the dash assemblies include significant flexibility, and are at the heart of any platform-derivative strategy. The dimensional range of derivative vehicles using alternative dashboards is currently severely restricted in view of the massive investment in tooling, fixturing, and real estate.
In contrast to conventional technologies, the AM mega-dash structure can be fully optimized for attachment of all key components that fit within the dash. The AM dash structure can be configured to include apertures and/or mounts for the various components of the assembly.
The AM dash can also be optimized to assist the occupant in impact events. In particular, the AM dash may be designed in a manner such that a majority of the frontal impact forces may be transferred into the underbody structure rather than the dash itself. Such a design protects the occupant's head and other vital organ areas. Further, the AM dash may be appended to interior safety items including, for example, a steering column, knee blockers, pedals and airbags, The latter are mounted to the cross car section which is attached to a pillar/cowl side. The steering column can be made to give way in the event of a head strike.
Auto experts expect vehicle crashes to reduce in frequency over the next several years. This prediction is due in large part to the advances in autonomous/assisted driving technologies. As these technologies mature, active safety may enable further mass optimization of transport structures. The vehicles can in such case be made considerably lighter and can operate with greater efficiency. The ability to concentrate on other design considerations can in turn lead to advances in the overall design of vehicles of the transportation system in general. For example, automated vehicles may potentially result in a significant reduction in traffic congestion. More vehicles can be accommodated on roads due to the precise automation of movement and the automated coordination between vehicles. These vehicles can be made to move more smoothly as automated vehicle systems tirelessly monitor conditions and execute necessary instructions to prevent crashes from occurring. Furthermore, increased active safety may also enable vehicle structural technologies to result in more environmentally-friendly transport structures. This in turn may curb down on emissions and pollutants, and the AM nature of transports would enable the transportation industry to become more eco-friendly.
In another aspect of the disclosure, an advanced vehicle system is configured to enable hydrogen to be utilized relatively safely as a fuel. The major advantage of hydrogen is that it is a clean fuel as its product after combustion is water. However, hydrogen storage and transport is not easy and gives rise to many safety considerations. For one, hydrogen is highly flammable. Currently, hydrogen vehicles function using fuel cells. These cells generate electricity via the combustion of hydrogen and charge one or more batteries. The stored electrical energy, like any electric car, is thereupon converted into kinetic energy for moving the vehicle. In short, these batteries power electric motors to achieve motion.
In an embodiment, AM may optimize the layout of the vehicle systems by providing significant freedom with respect to hydrogen tank, battery and motor placement. Conventional packaging systems are constrained by available tooling. That is, in current fuel cell vehicles, packaging the hydrogen gas is a major obstacle. To obtain approximately the same range as a vehicle using a conventional internal combustion engine, a hydrogen fuel cell powertrain may require gas tanks 2-3 times larger by volume, even when the hydrogen gas is compressed to 10,000 psi. In addition to requiring high volumes and pressures, hydrogen fuel tanks are limited to using cylindrical ends to withstand the high pressure, unlike conventional gas tanks which may conform to package constraints. Additionally, these high pressure hydrogen tanks are very expensive.
The underbody crash structure is illustrated in
Experts generally do not expect the battery efficiency driven by hydrogen to go higher. Accordingly, in an alternative exemplary embodiment, the hydrogen tank may store liquid hydrogen for use directly in an internal combustion engine. With AM technologies, hydrogen storage tanks can be designed with reinforcements to satisfy safety requirements, such as thick metal walls and custom handles to move the tank while avoiding contact with the cold temperatures. 3-D printing allows for flexibility in the placement of vehicle systems. Coupled with a modular design, customers may simply extract a used hydrogen tank and pop a filled one right in. To address some of the design and efficiency concerns around internal combustion engines (ICEs) using hydrogen as a fuel, the engines manufactured using 3-D printing can be made more efficient than current engines designed to handle smaller amounts of liquid hydrogen at a time.
The previous description is provided to enable any person ordinarily skilled in the art to practice the various aspects described herein. Various modifications to these exemplary embodiments presented throughout this disclosure will be readily apparent to those of ordinary skill in the art, and the concepts disclosed herein may be applied to aluminum alloys. Thus, the claims are not intended to be limited to the exemplary embodiments presented throughout the disclosure but are to be accorded the full scope consistent with the language claims. All structural and functional equivalents to the elements of the exemplary embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f), or analogous law in applicable jurisdictions, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”
The present disclosure claims the benefit under 35 U.S.C. 119 of U.S. Provisional Patent Application No. 63/128,746, filed Dec. 21, 2020 and entitled “ALUMINUM ALLOYS AND STRUCTURES”, which application is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63128746 | Dec 2020 | US |
