Patent Application
20200247003
The present invention relates to systems and processes for manufacturing components. More specifically, aspects of the present invention relate to methods and systems for the three-dimensional (3D) printing of ceramic matrix composite (CMC) structures which, unlike conventional methods, deposit a ceramic (solid) fiber composite in a desired pattern to form a desired structure.
Gas turbines comprise a casing or cylinder for housing a compressor section, a combustion section, and a turbine section. A supply of air is compressed in the compressor section and directed into the combustion section. The compressed air enters the combustion inlet and is mixed with fuel. The air/fuel mixture is then combusted to produce high temperature and high pressure gas. This working gas then travels past the combustor transition and into the turbine section of the turbine.
Generally, the turbine section comprises rows of vanes which direct the working gas to the airfoil portions of the turbine blades. The working gas travels through the turbine section, causing the turbine blades to rotate, thereby turning the rotor. The rotor is also attached to the compressor section, thereby turning the compressor and also an electrical generator for producing electricity. High efficiency of a combustion turbine is achieved by heating the gas flowing through the combustion section to as high a temperature as is practical. The hot gas, however, may degrade various metal turbine components, such as the combustor, transition ducts, vanes, ring segments, and turbine blades that it passes when flowing through the turbine.
For this reason, strategies have been developed to protect turbine components from extreme temperatures, such as the development and selection of high temperature materials adapted to withstand these extreme temperatures and cooling strategies to keep the components adequately cooled during operation. State of the art superalloys with additional protective coatings are commonly used for hot gas path components of gas turbines. In view of the substantial and longstanding development in the area of superalloys, however, it figures to be extremely difficult to further increase the temperature capability of superalloys.
For this reason, ceramic matrix composite (CMC) materials have been developed and increasingly utilized. These materials offer a high temperature resistance, e.g., up to or greater than 1200° C. Typically, CMC materials include a ceramic or a ceramic matrix material, either of which hosts a plurality of reinforcing fibers. The fibers may have a predetermined orientation to provide the CMC materials with additional mechanical strength. Generally, (fiber reinforced) ceramic matrix composites are manufactured by the infiltration of a matrix slurry (e.g., alumina, mullite, silicon-containing polymers, molten silicon) into a fiber preform. As such, the fibers are thus restricted to simple geometries with blunt curvatures as it is difficult to orient fibers at edges of the component into the complex shapes typical of gas turbine components. Also, for higher strength components, a three-dimensional weave structure in the preform may be required. Such weave structures are, however, difficult to infiltrate at high densities, thereby leaving pores as defects and crack initiators. Further, the weaving process itself may substantially weaken the fibers.
Three-dimensional printing techniques have been developed in order to deposit ceramic materials onto a previously deposited layer of a ceramic material. These 3D printing techniques for ceramic materials may be based on or include lithography, ultraviolet light, laser sintering, or binder jetting, free form extrusion, and the like. In many of these techniques, a binder is included and thereafter removed upon heating, thereby leaving a structurally poor ceramic material or a dense monolithic ceramic body. As such, these techniques do not allow for the deposition of advanced ceramic matrix composite structures with long fiber reinforcement.
In contrast to known approaches for forming ceramic matrix composite materials (wherein a ceramic or ceramic matrix material is introduced into a fibrous matrix or prepreg to form a ceramic matrix composite), aspects of the present invention enable a solid fiber material to be 3D-printed/co-extruded with a ceramic material (ceramic or ceramic matrix material). In certain aspects, a ceramic material is combined with a fiber material to form a ceramic fiber composite prior to 3D printing (depositing). The ceramic fiber composite may then be printed onto a working surface in as many layers as necessary and in a predetermined pattern to form a desired structure. The 3D printing of the ceramic fiber composite may be done before, after, or simultaneously with the printing of a ceramic material (without fiber loading) so as to produce the desired structures. Advantageously, the systems and processes described herein enable the 3D printing of ceramic fiber composites into components having complex shapes, and also enable the printing of ceramic fiber composites on complex 3D surfaces, such as gas turbine components. In this way, the systems and processes described herein allow for new compositions and the manufacture of components otherwise not yet considered at the present time. For example, components having distinct ceramic materials, fibers, and porosities within the same component are now much more accessible with aspects of the present invention. In addition, certain aspects of the present invention may eliminate the need for a coating deposition as a separate manufacturing step.
In accordance with one aspect of the present invention, there is provided a process for forming a ceramic fiber composite structure comprising: introducing a first ceramic material into a first solid fiber material to produce a first ceramic fiber composite; depositing the first ceramic fiber composite onto a working surface; and repeating the introducing and depositing steps until the structure is formed.
In accordance with another aspect, there is provided a process for manufacturing a ceramic fiber composite structure comprising: forming a first ceramic fiber composite; and sequentially forming a plurality of layers in a predetermined pattern corresponding to a desired shape of the structure, the sequentially forming comprising, for at least one layer, depositing the first ceramic fiber composite in accordance with the predetermined pattern.
In accordance with yet another aspect, there is provided an apparatus for forming a ceramic fiber composite structure comprising: a source of a first solid fiber material; a source of a first ceramic material; a first injector in fluid communication with the source of the first ceramic material and configured for introducing the first ceramic material into the first solid fiber material to provide a first ceramic fiber composite; and a first dispensing head configured to deposit the first ceramic fiber composite therefrom in a predetermined pattern.
The invention is explained in the following description in view of the drawings that show:
Referring now to the Figures,
The source 12 of first solid fiber material 14 may be in any form such as a spool (with fibers wound about a mandrel) or the like which conveys an amount of the first ceramic fiber material 14 for the system 10 as needed. In addition, the first solid fiber material 14 may comprise any suitable fiber material which provides a degree of added strength for the ceramic fiber composite. The fiber material 14 also has a desired thickness and a longitudinal length (L), which may extend through at least a portion of the system 10.
In an embodiment, the first solid fiber material 14 comprises a ceramic material. Without limitation, exemplary ceramic materials include alumina, mullite, aluminosilicate, yttria alumina garnet, silicon carbide, silicon nitride, silicon carbon nitride, molydisicilicide, zirconium oxide, titanium oxide, combinations thereof, and the like. In an embodiment, the fiber material 14 comprises an oxide material. In a particular embodiment, the fiber material 14 comprises a non-oxide material, such as silicon carbide, and the infiltration ceramic slurry comprises a ceramic-polymer mixture. In another particular embodiment, the fiber material 14 may comprise ceramic fibers sold under the trademark Nextel, such as Nextel 610, and 720 fibers. In addition, the fiber material 14 may be in any suitable form, such as a straight filament, a bundle or a roving of multiple fibers, a braid, or a rope. In still other embodiments, the fiber material may comprise non-ceramic materials, including but not limited to carbon, glass, polymeric, metal, or any other suitable fiber materials.
In an embodiment, the first solid fiber material 14 is delivered from the fiber source 12 such that a longitudinal section (L) of the fiber is repeatedly exposed (e.g., a loading region 15) to the first injector 20 as one of the first solid fiber material 14 and the first injector 20 is advanced past the other. As needed, an amount of a first ceramic material 18 may be introduced into the fiber material 14 by the first injector 20, or alternatively by any other suitable method or device. In this way, the first ceramic material 18 may be absorbed by and/or coated on the fiber material 14 along all or a portion of its longitudinal length to provide a first ceramic fiber composite 24. The amount of first ceramic material 18 introduced may be any suitable amount, such as from about 1 to about 500 μL per millimeter of length (L) of the associated fiber material, e.g., fiber material 14. As used herein, the term “about” refers to an amount that is ±5% of the stated amount.
In addition, the ceramic material 18 may be introduced into the solid first fiber material 14 by any suitable process and in any suitable form, such as a slurry or the like, to form the first ceramic fiber composite 24. In certain embodiments, the amount of ceramic material introduced to the first ceramic solid fiber composite may be a predetermined volume (vol.) % of the fiber material 14, such as from 1-75 vol. %, and in a particular embodiment, from 20-50 vol. %.
In an embodiment, the first solid fiber material 14 may comprise an uptake enhancement feature 26 associated therewith to facilitate uptake of the first ceramic material 18. In an embodiment, referring to
The source 16 of the first ceramic material 18 may comprise any suitable housing, such as a vessel or a syringe with a plunger, for containing a quantity of the first ceramic material 18. Similar to the first solid fiber material 14, the first ceramic material 18 may comprise an oxide material or a non-oxide material. In an embodiment, the first ceramic material 18 comprises an oxide material, such as zirconium oxide, titanium oxide, aluminum oxide, mullite, combinations thereof, and the like. In another embodiment, the first ceramic material 18 comprises a non-oxide material, such as a carbide material (e.g., an SiC material). In yet another embodiment, the first ceramic material 18 may comprise a ceramic-polymer mixture. In yet another embodiment, the ceramic material 18 may comprise a silicon-containing polymer, which may also comprise an oxide or non-oxide material. In certain embodiments, the first ceramic material 18 may comprise a mixture of two or more ceramic materials. Additionally, in some embodiments, the first solid fiber material 14 and the first ceramic material 18 may be of the same oxide or non-oxide material (e.g., oxide/oxide or non-oxide/non-oxide) or different materials of the same type (e.g. oxide1/oxide2, non-oxide1/non-oxide2). In other embodiments, the first solid fiber material 14 and the first ceramic material 18 may be of different types (e.g., oxide/non-oxide).
In accordance with an aspect, the first injector 20 is in fluid communication with the source 16 of the first ceramic material 18 such that the injector 20 introduces the first ceramic material 18 to the first solid fiber material 14 in a loading region 15 thereof. The amount of first ceramic material 18 delivered to the first solid fiber material 14 is without limitation and may, for example, be an amount which fully saturates the first solid fiber material 14 as portions of the first solid fiber material 14 travel past the first injector 20. In an embodiment, the amount of the first ceramic material 18 delivered to the first solid fiber material 18 by the first injector 20 may be from 1 to 500 μL per millimeter of length (L) of the fiber material, e.g., fiber material 18. Further, in an embodiment, the first ceramic material 16 has a solids fraction of from about 1 to about 90 wt %.
The skilled artisan would also readily appreciate that the amount of ceramic material 18 introduced to the first solid fiber material 14 may be dependent on properties of the first solid fiber material 14 and the first ceramic material 18, such as density, fiber thickness, viscosity, and the like. The first injector 20 may comprise any suitable structure that will allow for the active or passive introduction of a ceramic material, e.g., a first ceramic material 18, into an associated fiber material, e.g., first solid fiber material 14. In an embodiment, the first injector 20 comprises one or more nozzles 29, each of which may have any suitable outlet diameter and outlet shape suitable for the particular application. Further, in an embodiment, the first injector 20 may comprise a syringe comprising a suitable housing for storing an amount of a ceramic material therein, at least one nozzle 29, and a plunger for directing the ceramic material out of the syringe through the nozzle 29. The first injector 20 may further comprise any suitable valves, lines, pumps, or other components associated therewith as are necessary for operation thereof.
In accordance with an aspect, the first injector 20 may be disposed at any suitable angle relative to a longitudinal length (L) of the first solid fiber material 14 in order to introduce the first ceramic material 18 into the first solid fiber material 14 in the loading region 15 thereof to provide the ceramic fiber composite 24. In an embodiment, the angle is normal to the longitudinal length (L) of the first solid fiber material 14 as shown in
As would further be appreciated by the skilled artisan, the above embodiment describes a single ceramic material being introduced to the first solid fiber material 14. It is understood, however, that the present invention is not so limited. In other embodiments, the system 10 may include one or more additional ceramic sources in communication with first injector 20 and/or one or more additional injectors for introducing the additional ceramic material(s) into the first solid fiber material 14. Referring to
In an embodiment, as shown in
In still other embodiments, as shown in
In other embodiments, one or more ceramic materials may be mixed by a suitable mixing device and introduced into the first solid fiber material 14 by the first injector 20, the second injector 34, or a like device. In this way also, novel materials may further be created, such as a fiber material loaded into a ceramic blend having desired properties from each of a plurality of distinct ceramic materials, or having new properties altogether.
In accordance with another aspect, the system 10 allows for more than one type of fiber material to be deposited therefrom. To accomplish this, in an embodiment (and referring now to
Further, for ease of discussion, the source 44 of second solid fiber material 46, the second solid fiber material 46, the second ceramic fiber composite 48, the source of second ceramic material 30, the second ceramic material 32, the second injector 34, and the second dispensing head 50 may be the same or similar in structure or composition as described above for the corresponding first ones of each component (12, 14, 16, 18, 20, 22, 24). It is understood in the interest of brevity the possible embodiments for each composition will not be re-explained. It is further understood that each component may be of the same structure/type as that of its corresponding first component, or may be different in kind. By way of example only, the second solid fiber material 46 may be different from the first solid fiber material 14. Still further, it is further understood that the present invention is not so limited to first and second ones of the above components. In certain embodiments, still further fiber or ceramic materials (and corresponding components for the same) may be provided.
In accordance with another aspect, when the first ceramic fiber composite 24 or the second ceramic fiber composite 48 are printed (deposited), the first ceramic fiber composite 24 and the second ceramic fiber composite 48 may be deposited on or incorporated into an existing working surface 25 that comprises a ceramic material (the term “ceramic” is understood herein to include a ceramic or ceramic matrix material). In an embodiment, the working surface 25 comprises a ceramic material without fibers incorporated therein. In certain aspects, the system 10 may further include a structure for dispensing the ceramic material without fibers in a predetermined pattern. The ceramic fiber composite(s) may then be added onto/into the deposited ceramic only material. In this way, aspects of the present invention may not only print a ceramic fiber composite, but also add a fiber material to a ceramic material to build a component in contrast to known systems and process, wherein a ceramic material is incorporated into a fiber material, typically a fiber layup or preform.
Referring now to
As will be discussed below, in certain embodiments, the ceramic only dispensing head 52 may deposit the ceramic material 56 in a predetermined pattern in one or more layers on the working surface 25. Thereafter, an amount of a first or second ceramic fiber composite 24, 48 may be deposited on the ceramic material 56 (or vice-versa). Further thereafter, an additional layer of ceramic material 56 or a ceramic fiber composite material (e.g., 22, 48) may be deposited on the previously deposited layer(s) in a predetermined pattern. These steps may be repeated in any desired order until the component is formed. It is appreciated that any desired number of fiber dispensing heads or ceramic only dispensing heads may be provided in the system 10 or as modules to be added/removed from existing systems.
In accordance with another aspect, as mentioned, the dispensing heads (e.g., 22, 50, or 52) deposit the ceramic fiber composites or the ceramic material in a predetermined pattern. To accomplish this, a motor or other drive mechanism 58 may be associated with each dispensing head (e.g., 22, 50, or 52) to allow for deposition of the associated material on the working surface 25 in any coordinate position at a point in time. In an embodiment, the working surface 25 is configured to move with respect to the dispensing heads (e.g., 22, 50, and/or 52). In another embodiment, the dispensing heads (e.g., 22, 50, and/or 52) may be configured to move with respect to the working surface 25. In certain embodiments, as shown in
In addition, the system 10 may further comprise one or more controllers (e.g., controller 60) in electrical (wired or wireless) in communication with the drive mechanism 58 to facilitate the amounts, concentrations, order, location of, and extent of deposition of the materials, as well as the operation of any pumps, values, or the like, positions of the working surface 25 and/or dispensing heads 22, 50, or 52, or other parameter(s). For purposes of illustration,
The controller 60 may comprise a general or special purpose computer programmed with or software/hardware to carry out an intended function as described herein. As used herein, the term “computer” may include a processor, a microcontroller, a microcomputer, a programmable logic controller (PLC), a discrete logic circuit, an application specific integrated circuit, or any suitable programmable circuit or controlling device. The memory may include a computer-readable medium or a storage device, e.g., floppy disk, a compact disc read only memory (CD-ROM), or the like. In an embodiment, the controller 60 executes computer readable instructions for performing any aspect of the methods or for controlling any aspect of the systems or process steps described herein. As such, the controller 60 may be configured to execute computer readable instructions to monitor and/or adjust parameters such as: timing of deposition steps, the amounts, concentrations, order, location of, and extent of deposition of materials; the operation of pumps, valves, or the like; positions of the working surface and/or dispensing heads, or any other parameter(s). If necessary, the systems and processes described herein may employ one or more sensors for monitoring a desired parameter. Correspondingly, the controller 60 may comprise one or more inputs for receiving information from the one or more sensors.
In accordance with another aspect, when the first ceramic fiber composite 24, the second ceramic fiber composite 48, fiber material alone, or an additional fiber material is deposited onto the working surface 25, these components (which include a fiber material) may need to be cut, such as at an edge of the predetermined pattern. To accomplish this, as shown in
The cutting mechanism 62 may comprise any suitable component effective to cut the desired material at a desired time and location. In an embodiment, the cutting mechanism 62 comprises a device that cuts the fiber material mechanically. Without limitation, as shown in
In particular embodiments, activation of the cutting mechanism 62 may be automated, and thus programmed to cut the associated fiber material when the associated dispensing head or working surface 25 reaches a desired location/position or at a predetermined point in time. The cutting mechanism 62 may itself have a controller/microprocessor (of the type described above for controller 60) for automating these functions, or alternatively may be in electrical communication with an external controller, e.g., controller 60, for control of the operation thereof.
The apparatuses and products described herein may be suitable for manufacturing any ceramic matrix composite structures. The structure may be a newly manufactured component or a repair or addition to an existing component. In an aspect of the invention, the apparatuses and processes described herein are suitable for the manufacture of components having a complex 3D shape, e.g., an airfoil, shape. Thus, in an embodiment, the structure formed by the systems and processes described herein may comprise a gas turbine component. In certain embodiments, the gas turbine component may comprise a rotating component, such as a blade. In other embodiments, the gas turbine component may comprise a stationary component, such as a vane. By way of example,
In other embodiments, the systems and processes may be configured for 3D printing the material to repair/augment an existing component, such as any of the gas turbine components described herein. By way of example,
The operation of the systems as described herein, and the components therein, will be briefly described in the below paragraphs. It is however understood that the processes for operating the systems described herein and manufacturing component(s) therefrom is not so limited to the below description. Accordingly, the processes may include any additional or alternative steps that would be appreciated from the disclosure of the components described herein. Further, any component(s) or process step(s) described herein with respect to one embodiment may be combined with component(s) or process step(s) of any other embodiment described herein.
Referring now to
Next, as shown in
To accomplish the deposition of the ceramic fiber composite, as was shown in
To deposit the ceramic fiber composite(s) (24 or 48) onto the working surface 25 in the predetermined pattern, the associated dispensing head (e.g., 22, 50) may deposit the desired material and be moved with respect to the working surface 25 in any direction as shown in
Thereafter, an additional ceramic only layer or an additional ceramic fiber composite layer may be deposited on the next cross-sectional layer 106 to form a yet further cross-sectional layer. It is appreciated that this process may be repeated several times until the desired structure is formed. Still further, the combination of ceramic materials, fiber materials, ceramic fiber composites, and order of printing (deposition) of components may be quite large in number and is without limitation herein. In certain embodiments even, the fiber material may be deposited on the working surface 25 without loading of a ceramic material therein.
As noted above, when a fiber material as described herein (ceramic fiber composite or fiber material without ceramic material) is deposited, it may be desirable to cut the fiber material at a point in its path of deposition. Referring again to
In accordance with another aspect, as shown in
When ceramic fiber composites are printed as described herein, the cutting step allows complex geometries to be formed as the component's shape is not limited to an existing preform fiber shape. In accordance with another aspect, the deposition of the materials described herein can be provided in any desired order layer by layer until the component having a final desired composition, shape, and size is formed. Nothing in this disclosure is intended to limit the order of deposition of layers herein, each of which may comprise any of the material(s) described herein.
It is further contemplated that the deposited materials need not all be printed/deposited in the same direction and pattern. In accordance with another aspect, it is contemplated that a “weave-like” structure may be formed by depositing a first layer of the loaded ceramic material in a first x, y, or z direction and thereafter 3D printing a second layer over the first layer in a second x, y, or z direction distinct from the first direction. For example, as shown in
In the manufacture of a typical ceramic matrix composite material, a fiber preform is utilized which includes a weave structure, wherein fibers extending in one direction are loomed over and under fibers extending in another direction (e.g., transversely) to add strength to the overall material. In an aspect, the 3D printing of ceramic fiber composite material(s) as described herein improves upon these conventional techniques. As mentioned above, the weaving process may, in fact, significantly weaken the mechanical strength of the fibers. In contrast, the systems and processes described herein allow fibers to be oriented in different directions in the same material yet alleviate weakening of the fibers caused by typical weaving processes.
In accordance with another aspect, once all the desired layers are deposited to form the component 70 as described in any of the systems and processes described herein, the component 70 may be sintered or otherwise heated to a desired temperature. The sintering, for example, may take place by the application of energy, such as the application of heat, for any suitable duration at any desired temperature. In an embodiment, the component 70 (upon printing of all the layers) is sintered at a temperature of at least about 500° C., and in particular embodiment from 500° C. to 1200° C.—either isothermally or with a temperature gradient.
In accordance with an aspect, any existing system configured for the free form extrusion of ceramic materials can be modified with the components described herein to provide a system which deposits a ceramic fiber composite as described herein. Further, although aspects of the present invention have been explained in the context of manufacturing or repairing gas turbine components, as easily understood by those skilled in the art, the instant manufacturing concepts may be applied to other suitable fields and components.
While various embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.
This application claims priority and the benefit of the filing date of U.S. Provisional Application No. 62/247,458, filed Oct. 28, 2015, the entirety of which is hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2016/059029 | 10/27/2016 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62247458 | Oct 2015 | US |
