Patent Application
20240416424
The present disclosure relates to additive manufacturing methods and systems and, more particularly, to additive manufacturing methods and systems for the production of hierarchical design optimized components (e.g., composite or composite-like materials).
In general, some hierarchical composite materials can include an amorphous structure or metal glass, which can have excellent elastic modulus. However, this type of material tends to be brittle. A hybrid structure with crystalline grains in an amorphous matrix can be used to accommodate some plastic strain and impart ductility while maintaining high fatigue resistance and elastic modulus. The production of a real-life size part made from bulk metallic glass can be challenging because of high cooling rate requirements.
The present disclosure provides improved additive manufacturing methods and systems. More particularly, the present disclosure provides advantageous additive manufacturing methods and systems for the production of hierarchical design optimized components (e.g., composite or composite-like materials).
The present disclosure provides a methodology to produce hierarchical design optimized additively manufactured parts/materials that include an inhomogeneous structure with variable local mechanical properties across the entire volume.
The present disclosure provides for an additive manufacturing method for the production of a component including providing a material; utilizing additive manufacturing to fabricate the component from the material; and obtaining location-specific properties through in-situ controlling of a local cooling rate during the additive manufacturing to fabricate the component.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the component is a composite-like material.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the additive manufacturing comprises laser powder bed fusion.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the component is a hierarchical inhomogeneous composite-like material.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the component is an inhomogeneous structure with variable local mechanical properties across an entire volume of the inhomogeneous structure.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the material comprises bulk metallic glass.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the component comprises bulk metallic glass.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, wherein controlling the local cooling rate comprises utilizing modeling.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the modeling comprises utilizing an integrated computational fluid dynamics model and analytical models.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the modeling comprises utilizing a defect process map prediction fast acting model.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the modeling comprises utilizing solidification map prediction models.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the modeling comprises utilizing a phase field model for microstructure prediction and customization.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, wherein controlling the local cooling rate comprises utilizing a cryogenic cooling system internally installed in a laser powder bed machine, or use of computational fluid dynamics models to control the local cooling rate during layer deposition.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, wherein the cryogenic cooling system is a liquid nitrogen cryogenic cooling system designed specifically for laser powder bed fusion machines, and where a specific mask design and materials are used to prevent powder spatter during deposition.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the component comprises alternating hard-soft zones or features by controlling the high cooling rate and its application direction.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, wherein during additive manufacturing each layer of the component is initially built soft and then selected layers are hardened.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the additive manufacturing comprises utilizing a laser in a pulsed regime.
In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the component is a hybrid structure with crystalline grains in an amorphous matrix that accommodates plastic strain and imparts ductility while maintaining fatigue resistance and elastic modulus.
The above described and other features are exemplified by the following figures and detailed description.
Any combination or permutation of embodiments is envisioned. Additional features, functions and applications of the disclosed methods, systems and assemblies of the present disclosure will be apparent from the description which follows, particularly when read in conjunction with the appended figures. All references listed in this disclosure are hereby incorporated by reference in their entireties.
The following figures are example embodiments wherein the like elements are numbered alike.
Features and aspects of embodiments are described below with reference to the accompanying drawings, in which elements are not necessarily depicted to scale.
Example embodiments of the present disclosure are further described with reference to the appended figures. It is to be noted that the various steps, features and combinations of steps/features described below and illustrated in the figures can be arranged and organized differently to result in embodiments which are still within the scope of the present disclosure. To assist those of ordinary skill in the art in making and using the disclosed methods, systems and assemblies, reference is made to the appended figures, wherein:
The example embodiments disclosed herein are illustrative of additive manufacturing methods and systems for the production of hierarchical design optimized components (e.g., composite or composite-like materials). It should be understood, however, that the disclosed embodiments are merely examples of the present disclosure, which may be embodied in various forms. Therefore, details disclosed herein with reference to example additive manufacturing methods and systems and associated processes/techniques of fabrication and use are not to be interpreted as limiting, but merely as the basis for teaching one skilled in the art how to make and use the methods/systems and/or alternative methods/systems of the present disclosure.
The present disclosure provides improved additive manufacturing methods and systems. More particularly, the present disclosure provides advantageous additive manufacturing methods and systems for the production of hierarchical design optimized components (e.g., composite or composite-like materials).
As noted, some hierarchical composite materials can include an amorphous structure or metal glass, and this type of material can be brittle. A hybrid structure with crystalline grains in an amorphous matrix can be used to accommodate some plastic strain and impart ductility while maintaining high fatigue resistance and elastic modulus. It is noted that the production of a real-life size part made from bulk metallic glass can be challenging because of high cooling rate requirements.
In example embodiments, the present disclosure advantageously provides an additive manufacturing method (e.g., utilizing laser powder bed fusion-LPBF) for the production of a composite or composite-like material. It is noted that LPBF additive manufacturing offers a unique opportunity to control local cooling rate and the resulting hierarchical structures uniformly as parts are built layer wise.
The present disclosure provides a methodology to produce hierarchical design optimized additively manufactured parts/materials that include an inhomogeneous structure with variable local mechanical properties across the entire volume.
In example embodiments, hierarchical inhomogeneous structure/composite materials can be produced through the LPBF process. A novel LPBF method can be used to obtain location-specific properties through in-situ controlling of the local cooling rate during the additive manufacturing process. The change in the production of hierarchical graded composite or composite-like materials can depend on additions to the LPBF machine and methods of in situ cooling.
In some embodiments, the present disclosure provides for controlling the cooling rate through modeling and utilization of a cryogenic cooling system to induce a very high quenching or cooling rate for controlling the hierarchical structured composite or composite-like material using a LPBF process.
In example embodiments, the present disclosure provides for at least three features and/or method steps. A first feature and/or steps includes using process models to obtain a hierarchical structure containing different crystalline and amorphous grains.
A second feature and/or steps includes carefully designing the hierarchical structure to enable fabrication of compositionally graded composite or composite-like materials.
A third feature and/or steps includes combining multiple compositions and process parameter sets (e.g., for different cooling rate) to obtain simultaneous variation in microstructure type (e.g., amorphous/crystalline) and microstructural features (e.g., grain size and aspect ratio). In addition, a cryogenic cooling system can be used to cool the melt pool very quickly and effectively, generating a sharp heat boundary and/or reduce heat diffusion around the melt pool, generating a sharp heat boundary.
The present disclosure provides that additively manufactured parts can be produced with variable mechanical properties by in-situ controlling of the cooling rate. One embodiment is a hierarchal or “composite” or composite-like material with alternating hard-soft zones or features, where in one instantiation hard grains provide the overall strength of the material, and soft grains work as crack-trapping or stopping sites-see
The cooling rate has a direct influence on the local dislocation density and residual stress which in turn controls the hardness and fatigue strength of the material. The local bulk variability of properties is taking advantage of the fact that additive manufacturing builds parts by sequential layers. In example embodiments, the present disclosure provides to build each layer initially soft, and then selected layers are hardened.
That can be achieved by a special set of parameters to ensure small thermal gradients and consequently small cooling rates. The cooling rate can be predicted offline using a developed model, illustrated in
Another way is to use a laser in a pulsed regime with slow power decay for local annealing. Then the laser makes a second path for the same layer with normal speed and power or works in a pulsed regime with fast power decay. At this second path, the laser generates hard quenched structural components such as lines and pillars by taking advantage of generic fast cooling rates of typically a very small (e.g., of the order of hundreds of microns) melt pool in metal environments as shown in
A somewhat similar approach can be used to harden the metal surface by heating the surface by eddy currents and then cooling it fast by rapid heat removal through the bulk of the metal. However, this conventional method provides only surface hardening while the methods of the present disclosure generate the hard/soft grain structure throughout the part bulk.
The extreme high cooling rate or fast quenching process can be enhanced by spraying liquid nitrogen (LN) at the sides of the laser spot. For this purpose, a cryogenic cooling system 100 (
The hard lines and pillars can be made of bulk metallic glass (BMG) if the composition and cooling rates are appropriate. An advantage of the cooling method of the present disclosure is creation of sharper boundaries between soft and hard grains.
Hierarchal structures can be designed and built by additive manufacturing with the same powder feed stock, but with location-specific processing to create desired properties to enable a meso-scale structural material system.
Another embodiment is a hybrid structure with crystalline grains in an amorphous matrix that accommodates some plastic strain and imparts ductility while maintaining high fatigue resistance and elastic modulus (
There are many benefits of the methods, systems and assemblies of the present disclosure, including, without limitation: controlling material properties; producing completely novel functional composite or composite-like materials; advancing the LPBF process technology; eliminating or reducing defects in the parts; fatigue and yield properties improvements with grain refinement; light weighting of aerostructures; fabrication of strain wave gears with high transmission ratio, actuators; and/or environmental protection for naval applications.
While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.
The ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of “up to 25 wt. %, or, more specifically, 5 wt. % to 20 wt. %”, is inclusive of the endpoints and all intermediate values of the ranges of “5 wt. % to 25 wt. %,” etc.). “Combinations” is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms “first,” “second,” and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” and “the” do not denote a limitation of quantity and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. “Or” means “and/or” unless clearly stated otherwise. Reference throughout the specification to “some embodiments”, “an embodiment”, and so forth, means that a particular element described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments. A “combination thereof” is open and includes any combination comprising at least one of the listed components or properties optionally together with a like or equivalent component or property not listed.
Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this application belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.
Although the systems and methods of the present disclosure have been described with reference to example embodiments thereof, the present disclosure is not limited to such example embodiments and/or implementations. Rather, the systems and methods of the present disclosure are susceptible to many implementations and applications, as will be readily apparent to persons skilled in the art from the disclosure hereof. The present disclosure expressly encompasses such modifications, enhancements and/or variations of the disclosed embodiments. Since many changes could be made in the above construction and many widely different embodiments of this disclosure could be made without departing from the scope thereof, it is intended that all matter contained in the drawings and specification shall be interpreted as illustrative and not in a limiting sense. Additional modifications, changes, and substitutions are intended in the foregoing disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure.
