Apparatus and process for freeform fabrication of composite reinforcement preforms

• US 6,214,279 B1
• Filed: 10/02/1999
• Issued: 04/10/2001
• Est. Priority Date: 10/02/1999
• Status: Expired due to Fees

• Current Assignee: Nanotek Instruments Group, LLC
• Original Assignee: Nanotek Instruments, Inc.
• Inventors: Jang, Bor Z., Liu, Junhai, Yang, Junsheng, Wu, Liangwei
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US09/410,913
• Time in Patent Office: 556 Days
• Field of Search: 264/40.1, 264/308, 264/401, 264/482, 264/483, 264/485, 264/488, 264/489, 264/492, 264/494, 425/135, 425/141, 425/145, 425/375, 347/1, 700/119
• US Class Current: 264/482
• CPC Class Codes: B22F 1/00 Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• CPC Class Codes: B22F 10/14 by jetting of binder onto a bed of metal powder
• CPC Class Codes: B22F 10/43 characterised by material
• CPC Class Codes: B22F 10/80 Data acquisition or data processing
• CPC Class Codes: B22F 12/53 Nozzles
• CPC Class Codes: B22F 12/55 Two or more means for feeding material
• CPC Class Codes: B22F 12/90 Means for process control, e.g. cameras or sensors
• CPC Class Codes: B29C 41/52 Measuring, controlling or regulating
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B29K 2105/06 containing reinforcements, fillers or inserts
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A solid freeform fabrication process and apparatus for making a three-dimensional reinforcement shape. The process comprises the steps of (1) operating a multiple-channel material deposition device for dispensing a liquid adhesive composition and selected reinforcement materials at predetermined proportions onto a work surface; (2) during the material deposition process, moving the deposition device and the work surface relative to each other in an X-Y plane defined by first and second directions and in a Z direction orthogonal to the X-Y plane so that the materials are deposited to form a first layer of the shape; (3) repeating these steps to deposit multiple layers for forming a three-dimensional preform shape; and (4) periodically hardening the adhesive to rigidize individual layers of the preform. These steps are preferably executed under the control of a computer system by taking additional steps of (5) creating a geometry of the shape on the computer with the geometry including a plurality of segments defining the preform shape and each segment being preferably coded with a reinforcement composition defining a specific proportion of different reinforcement materials; (6) generating programmed signals corresponding to each of the segments in a predetermined sequence; and (7) moving the deposition device and the work surface relative to each other in response to these programmed signals. Preferably, the system is also operated to generate a support structure for any un-supported feature of the 3-D preform shape.

Claims

1. A process for fabricating a net-shape reinforcement preform for a composite material part, in a layer-by-layer manner comprising

(a) providing a work surface lying substantially parallel to an X-Y plane of an X-Y-Z Cartesian coordinate system defined by three mutually perpendicular X-, Y- and Z-axes;

(b) positioning a material deposition device at a predetermined initial distance from said work surface, said deposition device comprising at least a reinforcement dispensing tool and an adhesive dispensing tool;

(c) operating and moving said material deposition device relative to said work surface along selected directions in said X-Y plane to deposit first layer of selected reinforcement and adhesive compositions onto said work surface, said first layer being of a predetermined cross-sectional shape on said X-Y plane and a predetermined thickness in said Z-axis direction;

(d) moving said material deposition device away from said work surface along said Z-axis direction by a predetermined distance,

(e) operating and moving said material deposition device to deposit another layer of selected reinforcement and adhesive compositions of another predetermined cross-sectional shape and thickness, and

(f) repeating steps (d) and (e) to deposit multiple layers of reinforcement and adhesive compositions for forming said net-shape reinforcement preform.

2. A process for fabricating a net-shape reinforcement preform as defined in claim 1, wherein each said reinforcement composition is selected from the group of reinforcements consisting of short fiber, long fiber, whisker, spherical particle, ellipsoidal particle, flake, small platelet, small ribbon, disc, or a combination thereof.

3. A process as defined in claim 1, wherein step (c), (e) and/or (f) further comprises an additional step of hardening said adhesive to help maintain the shape of individual layers.

4. A process as defined in claim 1, wherein step (c), (e) and/or (f) comprises sub-steps of (i) depositing a layer of reinforcement and adhesive to an initial layer thickness greater than said predetermined thickness, (ii) compressing said layer to said predetermined thickness, and (iii) hardening said adhesive to help maintain the shape of individual layers.

5. A process as defined in claim 1, wherein step (c), (e) and/or (f) comprises sub-steps of employing a reinforcement dispensing tool to deposit first-type reinforcement to first portion of an individual layer and employing the same or a different reinforcement dispensing tool to deposit second-type reinforcement to a second portion of said individual layer for forming a hybrid preform shape of multi-reinforcements.

6. A process as defined in claim 3, wherein said adhesive hardening step is promoted by using an energy source selected from a group consisting of ultra-violet light, infrared, microwave, Gamma radiation, laser, electron beam, ion beam and plasma.

7. A process as defined in claim 1, further comprising the steps of:

creating a geometry of said three-dimensional preform on a computer with said geometry including a plurality of segments defining the preform;

generating programmed signals corresponding to each of said segments in a predetermined sequence; and

moving said material deposition device and said work surface relative to each other in response to said programmed signals.

8. A process as defined in claim 1, further comprising the steps of:

creating a geometry of said three-dimensional preform on a computer with said geometry including a plurality of segments defining the preform;

each of said segments being coded with a selected reinforcement composition;

generating programmed signals corresponding to each of said segments in a predetermined sequence; and

operating said material deposition device in response to said programmed signals to selectively dispense and deposit said adhesive and selected reinforcement compositions, one reinforcement composition at a time, while said material deposition device and said work surface are moved relative to each other in response to said programmed signals in said predetermined sequence.

9. A process as defined in claim 1, wherein said moving step includes the step of moving said material deposition device and said work surface relative to each other along selected directions on said X-Y plane according to a first predetermined pattern to form an outer boundary from selected reinforcement and adhesive compositions on said work surface, said outer boundary defining an exterior surface of said preform.

10. A process as defined in claim 9, wherein said outer boundary defines an interior space in said preform, and said moving step further includes the step of moving said material deposition device and said work surface relative to each other along selected directions on said X-Y plane according to at least one other predetermined pattern to fill said interior space with selected reinforcement and adhesive compositions.

11. A process as defined in claim 10, further comprising the steps of:

creating a geometry of said three-dimensional preform on a computer with said geometry including a plurality of segments defining the preform and each of said segments being coded with a selected reinforcement composition; and

generating programmed signals corresponding to each of said segments in a predetermined sequence, wherein said programmed signals determine said movement of said material deposition device and said work surface relative to each other in said first predetermined pattern and said at least one other predetermined pattern.

12. A process as defined in claim 1, further comprising

using dimension sensor means to periodically measure dimensions of the object being built;

and

using a computer to determine the thickness and outline of individual layers of said reinforcement and adhesive compositions in accordance with a computer aided design representation of said preform;

said computing step comprising operating said computer to calculate a first set of logical layers with specific thickness and outline for each layer and then periodically re-calculate another set of logical layers after periodically comparing the dimension data acquired by said sensor means with said computer aided design representation in an adaptive manner.

13. A process as defined in claim 1, wherein said operation of a material deposition device includes the operation of a separate support material dispensing tool and wherein said process further comprises the steps of:

creating a geometry of said three-dimensional preform on a computer with said geometry including a plurality of segments defining the preform;

evaluating the data files representing said preform to locate any un-supported feature of the preform and, responsive to said evaluation step, determining a support structure for the un-supported feature and creating a plurality of segments defining said support structure;

generating programmed signals corresponding to each of said segments defining both said preform and said support structure in a predetermined sequence; and

moving said material deposition device and said work surface relative to each other in response to said programmed signals for building said preform and said support structure.

14. A process as defined in claim 1, wherein said operation of a material deposition device includes the operation of a separate support material dispensing tool and wherein said process further comprises the steps of:

creating a geometry of said three-dimensional preform on a computer with said geometry including a plurality of segments defining the preform;

evaluating the data files representing said preform to locate any un-supported feature of the preform and, responsive to said evaluation step, determining a support structure for the un-supported feature and creating a plurality of segments defining said support structure;

each of said segments for the preform being coded with a selected reinforcement composition and each of said segments for the support structure being coded with a support material composition;

generating programmed signals corresponding to each of said segments in a predetermined sequence;

operating said material deposition device in response to said programmed signals to selectively dispense and deposit said selected reinforcement, adhesive and support material compositions; and

moving said material deposition device and said work surface relative to each other in response to said programmed signals for building said preform shape and said support structure.

26. A process as set forth in claim 1, further comprising additional step of impregnating said reinforcement preform with a solidifying matrix material to form a net-shape three-dimensional composite part.

28. A process as set forth in claim 1, further comprising additional steps of

(f) burning off at least partially said adhesive composition;

and

(g) impregnating said reinforcement preform with a solidifying matrix material to form a net-shape three-dimensional composite part.

15. Solid freeform fabrication apparatus for making a three-dimensional reinforcement preform shape, comprising:

(a) a material deposition device comprising

a liquid adhesive dispensing tool that comprises (1) at least a flow channel being supplied with a hardenable liquid adhesive composition, (2) at least one nozzle having, on one end, a fluid passage in flow communication with said at least one channel and, on another end, a discharge orifice of a predetermined size, and (3) actuator means located in control relation to said channel for activating delivery of said liquid adhesive composition through said discharge orifice;

a reinforcement dispensing tool that comprises (1) at least a flow channel being supplied with a solid reinforcement composition, (2) at least one nozzle having, on one end, a flow passage in flow communication with said flow channel and, on another end, a discharge orifice of a predetermined size, and (3) valve means located in control relation with said flow channel;

(b) an object-supporting work surface at a predetermined initial distance from said discharge orifices to receive said liquid adhesive and reinforcement compositions therefrom;

(c) motion devices coupled to said work surface and said material deposition device for moving said material deposition device and said work surface relative to each other in a plane defined by first and second directions and in a third direction orthogonal to said plane to deposit said liquid adhesive and reinforcement compositions into a three-dimensional shape.

16. Apparatus as set forth in claim 15, wherein said liquid adhesive dispensing tool comprises a device selected from the group consisting of an ink jet print-head with thermally activated actuator means, an ink jet print-head with piezo-electrically activated actuator means, and an air gun with compressed air-powered actuator means.

17. Apparatus as set forth in claim 15, further comprising:

a computer-aided design computer and supporting software programs operative to create a three-dimensional geometry of a desired preform shape, to convert said geometry into a plurality of segments defining the shape, and to generate programmed signals corresponding to each of said segments in a predetermined sequence; and

a three-dimensional motion controller electronically linked to said computer and said motion devices and operative to actuate said motion devices in response to said programmed signals for each of said segments received from said computer.

18. Apparatus as set forth in claim 17, wherein said supporting software programs comprise:

means for evaluating the data files representing the geometry of said preform shape to locate any un-supported feature of the preform shape;

means, responsive to the evaluating means locating an un-supported feature, for defining a support structure for said un-supported feature;

means for creating a plurality of segments defining said support structure; and

means for generating programmed signals required by said material deposition device to fabricate said support structure.

19. Apparatus as set forth in claim 17, further comprising:

sensor means electronically linked to said computer and operative to periodically provide layer dimension data to said computer;

supporting software programs in said computer operative to perform adaptive layer slicing to periodically create a new set of layer data comprising segments defining the shape in accordance with said layer dimension data acquired by said sensor means, and to generate programmed signals corresponding to each of said segments in a predetermined sequence.

20. Apparatus as set forth in claim 15, further comprising compacting means coupled to said material deposition device for compacting the deposited reinforcement and adhesive composition.

21. Apparatus as set forth in claim 15, wherein said liquid adhesive composition is selected from the group consisting of photo-curable resins including laser-curable resins, microwave-curable resins, heat-curable resins, electron beam-curable resins, ion beam curable resins, plasma curable resins, and sol-gel compositions.

22. Apparatus as set forth in claim 15, wherein said liquid adhesive composition comprises an fast-vaporizing liquid.

23. Apparatus as set forth in claim 15 wherein said material deposition device comprises a support material deposition tool for building a support structure.

24. Apparatus as set forth in claim 15 wherein said reinforcement dispensing tool comprises a multi-channel pneumatic plug-phase delivery device comprising:

multiple particulate-supplying chambers;

pipe means in flow communication with said chambers to receive plugs of particulate material therefrom;

a supply of compressed air and valve means in control relation to said chambers and said pipe means to create said plugs of particulate material on demand in said pipe means;

a dispensing nozzle having, on one end, a flow passage in flow communication with said pipe means and, on another end, a discharge orifice of a predetermined size to dispense said particulate material therethrough.

25. A process for making multi-reinforcement a three-dimensional preform shape of spatially tailored material compositions, comprising the steps of

creating a geometry of said shape on a computer, said geometry including a plurality of segments defining said shape;

each of said segments being coded with a specific reinforcement composition;

evaluating the geometry data files representing said shape to locate any un-supported feature of the shape, followed by defining a support structure for the un-supported feature and creating a plurality of segments defining said support structure;

generating program signals corresponding to each of said segments for both said preform shape and said support structure in a predetermined sequence;

providing a material deposition device capable of (a) dispensing a liquid adhesive composition, (b) dispensing, for each spatial location, a selected reinforcement composition for said shape, and (c) dispensing support material for building said support structure;

operating said material deposition device to deposit adhesive, reinforcement and support material compositions onto an object-supporting work surface;

during said deposition step, moving said material deposition device and said work surface in response to said programmed signals relative to each other in a plane defined by first and second directions and in a third direction orthogonal to said plane in a predetermined sequence of movements such that said material compositions are deposited in free space as a plurality of segments sequentially formed so that the last deposited segment overlies at least a portion of the preceding segment in contact therewith to thereby form said support structure and said multi-reinforcement three-dimensional preform shape.

27. A process as set forth in claim 25, further comprising additional step of impregnating said reinforcement preform with a solidifying matrix material to form a net-shape three-dimensional composite part.

29. A process as set forth in claim 25, further comprising additional steps of

burning off at least partially said adhesive composition; and

impregnating said reinforcement preform with a solidifying matrix material to form a net-shape three-dimensional composite part.