Layer manufacturing using deposition of fused droplets

• US 6,401,001 B1
• Filed: 07/22/1999
• Issued: 06/04/2002
• Est. Priority Date: 07/22/1999
• Status: Expired due to Term

• Current Assignee: Nanotek Instruments Group, LLC
• Original Assignee: Nanotek Instruments, Inc.
• Inventors: Yang, Junsheng, Pan, Lijun, Jang, Bor Z., Liu, Junhai
• Primary Examiner(s): PATEL, RAMESH B
• Application Number:
  US09/358,871
• Time in Patent Office: 1,048 Days
• Field of Search: 700/97, 700/98, 700/117, 700/118, 700/119-120, 700/163, 345/419, 345/420, 264/9, 264/407, 264/512-516, 264/633, 264/642, 264/75, 264/308, 264/317, 427/466, 427/472, 427/470, 427/249.14, 427/248.1, 427/255.4, 427/595, 427/553, 204/192.15, 204/192--19, 204/192.3, 204/298.12
• US Class Current: 700/118
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• 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 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: H01L 21/288 from a liquid, e.g. electrolytic deposition
• CPC Class Codes: H01L 21/6715 Apparatus for applying a liquid, a resin, an ink or the like H01L21/67126 takes precedence
• CPC Class Codes: H05K 3/102 by bonding of conductive powder, i.e. metallic powder H05K3/12 takes precedence
• CPC Class Codes: H05K 3/125 by ink-jet printing
• CPC Class Codes: Y10S 977/775 Nanosized powder or flake, e.g. nanosized catalyst
• CPC Class Codes: Y10S 977/89 Deposition of materials, e.g. coating, cvd, or ald

Abstract

A solid freeform fabrication process and apparatus for making a three-dimensional object. The process comprises the steps of (1) positioning a material deposition sub-system a selected distance from a target surface, (2) operating this sub-system to deposit materials onto the target surface by carrying out the sub-steps of (a) operating a multiple-channel powder delivery device for supplying selected powder compositions at a predetermined flow rate to travel toward the target surface and (b) operating a focused energy beam to produce a fusion zone through which the powder particles, preferably in micron or nanometer sizes, are melted while in flight, thereby producing liquid droplets traveling to deposit onto the target surface, and (3) during the material deposition process, moving the deposition sub-system and the target surface relative to one another along selected directions in a plane defined by first and second coordinate directions and in a third direction orthogonal to this plane to form deposition materials into a three dimensional shape. These steps are preferably executed under the control of a computer system. Preferably, the system is also operated to generate a support structure for any un-supported feature of the object.

Claims

1. Solid freeform fabrication apparatus for making a three-dimensional object, comprising:

(a) a target surface;

(b) a material deposition sub-system, disposed in working proximity to said target surface, comprising;

a powder delivery device comprising (1) a multiplicity of flow channels with each channel having first and second ends, said first end being supplied with particles of a fine powder composition and said second end having a discharge orifice of a predetermined size to dispense said powder composition therethrough, and (2) valve means located in control relation to each of said channels for regulating the flow of said powder particles through said discharge orifice toward said target surface;

the flow of said dispensed powder particles forming a travel path;

a focused energy beam disposed in working proximity to said target surface and operative to intersect said powder travel path for producing a fusion zone in which said powder particles are at least partially melted to form liquid droplets, said liquid droplets continuing to travel along said path for deposition onto said target surface;

(c) motion devices coupled to said target surface and said material deposition sub-system for moving said deposition sub-system and said target surface relative to one another along selected directions in a plane defined by first and second coordinate directions and in a third coordinate direction orthogonal to said plane to form said deposition materials into a three-dimensional shape.

2. Apparatus as set forth in claim 1, wherein said focused energy beam comprises a laser beam.

3. Apparatus as set forth in claim 1, further comprising:

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

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

4. Apparatus as set forth in claim 3 wherein said machine controller and said computer comprise means for controlling said valve means for regulating the flow of said powder compositions.

5. Apparatus as set forth in claim 3, wherein said material deposition sub-system further comprises a separate material dispensing tool and said supporting software programs comprise:

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

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 separate material dispensing tool to fabricate said support structure.

6. Apparatus as set forth in claim 3, 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 object 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.

7. Apparatus as set forth in claim 1 wherein said powder delivery device further comprises a ventilation system for removing unused powder particles proximate or on said target surfaces.

8. Apparatus as set forth in claim 1 wherein said powder delivery device is positioned below said target surface in such a fashion that the material deposition takes place approximately upwardly from underneath said target surface.

9. Apparatus as set forth in claim 1, wherein said focused energy beam comprises an ion beam.

10. Apparatus as set forth in claim 1, wherein said focused energy beam comprises an electron beam.

11. Apparatus as set forth in claim 1, wherein said focused energy beam comprises a focused induction heating zone.

12. Apparatus as set forth in claim 1, wherein at least one of said channels comprises a dynamic powder sieving and dispensing device comprising:

first chamber in flow communication with said first end of said channel to receive fine powder particles therefrom,

first sieve means with first and second surfaces substantially parallel to each other, said first surface in flow communication with said first chamber;

said sieve means being equipped with a vibration facilitator; and

second chamber having proximal and distal ends, said proximal end in flow communication with said second surface of said first sieve means and said distal end in flow communication with said discharge orifice.

13. Apparatus as set forth in claim 12, wherein said second chamber is further equipped with a particle counting device.

14. Apparatus as set forth in claim 12, further comprising:

a charge injector in flow communication with at least one of said chambers for making powder particles therein electrostatically charged, and

an electrode disposed in working proximity to said discharge orifice to direct the flow of said charged particles.

15. Apparatus as set forth in claim 1, wherein at least one of said channels comprises a dynamic powder sieving and dispensing device comprising:

first chamber in flow communication with said first end of said channel to receive fine powder particles therefrom,

first sieve means with first and second surfaces substantially parallel to each other, said first surface in flow communication with said first chamber;

said sieve means being equipped with a vibration facilitator,

second chamber having proximal and distal ends, said proximal end in flow communication with said second surface of said first sieve means;

said second chamber being equipped with a particle counting device,

valve means in control relation with said distal end of said second chamber and in flow communication with said discharge orifice.

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

a charge injector in flow communication with at least one of said chambers for making powder particles therein electrostatically charged, and

an electrode disposed in working proximity to said discharge orifice to direct the flow of said charged particles.

17. A freeform fabrication process for making a three-dimensional object, said process comprising the steps of:

positioning a material deposition sub-system a selected distance from a target surface;

operating said sub-system, comprising a multiple-channel powder delivery device and a focused energy beam, to deposit selected materials onto said target surface comprising the sub-steps of (a) operating said powder delivery device for ejecting powder particles of selected material compositions traveling along a path toward said target surface;

(b) operating said energy beam to intersect said powder travel path for producing a fusion zone in which said particles are at least partially melted during travel, forming liquid droplets that travel to deposit onto said target surface;

during said material deposition process, moving said deposition sub-system and said target surface relative to one another along selected directions in a plane defined by first and second coordinate directions and in a third coordinate direction orthogonal to said plane to form deposition materials into a three dimensional shape.

18. A process as set forth in claim 17, wherein the moving step includes the sub-steps of:

(a) moving said deposition sub-system and said target surface relative to one another in a direction parallel to said plane to deposit a first portion of a first layer from first powder composition onto said target surface;

(b) moving said deposition sub-system and said target surface relative to one another in a direction parallel to said plane to form a second portion of said first layer from a second powder composition onto said target surface;

(c) repeating step (b) for completing the deposition of predetermined materials for said first layer;

(d) moving said material deposition sub-system and said target surface away from one another in said third direction by a predetermined layer thickness; and

(e) dispensing and depositing a second layer of predetermined materials from a second set of powder compositions onto said first layer while simultaneously moving said target surface and said deposition sub-system relative to one another in selected directions parallel to said plane, whereby said second layer adheres to said first layer.

19. A process as set forth in claim 18, comprising additional steps of forming multiple layers of said deposition materials on top of one another by repeated dispensing and depositing of said deposition materials from said deposition sub-system as said target surface and said deposition sub-system are moved relative to one another in a direction parallel to said plane, with said deposition sub-system and said target surface being moved away from one another in said third direction by a predetermined layer thickness after each preceding layer has been formed.

20. A process as set forth in claim 17, further comprising the steps of:

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

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

moving said deposition sub-system and said target surface relative to each other in response to said programmed signals.

21. A process as set forth in claim 17, further comprising the steps of:

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

each of said segments being coded with a selected material composition corresponding to one or more of said powder compositions combined at a predetermined proportion;

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

operating said material deposition sub-system in response to said programmed signals to selectively dispense and deposit said selected deposition materials;

moving said deposition sub-system and said target surface relative to one another in response to said programmed signals.

22. A process as set forth in claim 17, wherein said moving step includes the step of moving said deposition sub-system and said target surface relative to one another in selected directions parallel to said plane according to a first predetermined pattern to form an outer boundary from selected powder compositions on said target surface, said outer boundary defining an exterior surface of said object.

23. A process as set forth in claim 22, wherein said outer boundary defines an interior space in said object, and said moving step further includes the step of moving said deposition sub-system and said target surface relative to one another in selected directions parallel to said plane according to at least one other predetermined pattern to fill said interior space with selected deposition materials.

24. A process as set forth in claim 23, further comprising the steps of:

creating a geometry of said three-dimensional object on a computer, said geometry including a plurality of segments defining said object; and

generating program signals corresponding to each of said segments in a predetermined sequence, wherein said program signals determine said movement of said deposition sub-system and said target surface relative to one another in said first predetermined pattern and said at least one other predetermined pattern.

25. A process as set forth in claim 23 wherein said interior space is deposited with a spatially controlled material composition comprising two or more distinct types of materials.

26. A process as set forth in claim 25 wherein said interior space is deposited with a material composition in continuously varying concentrations of distinct materials in three-dimensional part space to form a spatially controlled material composition part.

27. A process as set forth in claim 25 wherein said distinct types of materials are deposited at discrete locations in three-dimensional part space to form a spatially controlled material composition part.

28. A process as set forth in claim 17, further comprising:

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

using a computer to determine the thickness and outline of individual layers of said deposition materials in accordance with a computer aided design representation of said object;

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.

29. A process as set forth in claim 17, wherein said operation of a deposition sub-system includes the operation of a separate material dispensing tool and wherein said process further comprises the steps of:

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

evaluating the data files representing said object to locate any un-supported feature of the object 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 program signals corresponding to each of said segments for both said object and said support structure in a predetermined sequence;

moving said deposition sub-system and said work surface relative to each other in response to said programmed signals for said material deposition sub-system to build said object and said support structure.

30. A process as set forth in claim 17, wherein said operation of a deposition sub-system includes the operation of a separate material dispensing tool and wherein said process further comprises the steps of:

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

evaluating the data files representing said object to locate any un-supported feature of the object 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 object and the support structure being coded with a selected material composition;

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

operating said material deposition sub-system in response to said programmed signals to selectively dispense and deposit said selected deposition materials; and

moving said deposition sub-system and said target surface relative to one another in response to said programmed signals for building said object and said support structure.

31. A process as set forth in claim 17, wherein said powder delivery device is positioned below said target surface so that the deposition of materials takes place generally upwardly from underneath.

32. Process as set forth in claim 17, wherein said powder particles comprising solid particles surface-coated with a lower melting point material.

33. A freeform fabrication process for making a three-dimensional object, said process comprising the steps of:

(1) positioning a material deposition sub-system a selected distance from a target surface;

said deposition sub-system comprising a multiple-channel powder delivery device and a focused energy beam;

(2) operating said deposition sub-system to deposit selected materials onto said target surface comprising the sub-steps of (a) operating said powder delivery device for directing first powder composition toward a first area of said target surface;

(b) operating said focused energy beam to produce a fusion zone near said first area for melting said powder to form liquid droplets traveling to deposit a first portion of said object onto said target surface;

(c) moving said deposition sub-system and said target surface relative to one another along selected directions in a plane defined by first and second coordinate directions and, during said moving step, operating said deposition sub-system to deposit a second portion of said first layer onto said target surface;

(d) repeating steps (a), (b) and (c) to complete the deposition of a cross-section of materials for said first layer of the object, the boundary of said cross-section defining a complementary un-deposited region;

(3) operating a dispensing tool to deposit a support material to at least a portion of said complementary region;

(4) moving said deposition sub-system and said target surface away from one another by a predetermined layer thickness in a third direction orthogonal to said plane; and

(5) repeating the above operating and moving steps (2), (3) and (4) to form multiple layers of deposition materials, one adhering upon another, into a three dimensional shape.

34. A process as set forth in claim 33, further comprising the step of removing at least a portion of said support material following the completion of one of said multiple layers.

35. A process as set forth in claim 33, wherein said operating and moving steps are controlled by a computer.