Three-dimensional product manufacture using masks

• US 5,940,674 A
• Filed: 04/09/1997
• Issued: 08/17/1999
• Est. Priority Date: 04/09/1997
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Cima, Michael J., Sachs, Emanuel M.
• Primary Examiner(s): Jenkins, Daniel J.
• Application Number:
  US08/831,636
• Time in Patent Office: 860 Days
• Field of Search: 419/2, 419/7, 419/36, 419/27, 419/54, 264/413, 264/414, 264/434, 264/63, 425/78
• US Class Current: 419/2
• CPC Class Codes: B22F 10/14 by jetting of binder onto a bed of metal powder
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/11 Making porous workpieces or articles
• CPC Class Codes: B22F 3/115 by spraying molten metal, i.e. spray sintering, spray casting
• 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: 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: Y02P 10/25 Process efficiency

Abstract

A process for making a component includes the steps of: depositing a layer of a porous material; positioning a mask near to the deposited layer; applying a bonding material that will cause any contacted portions of the porous material to become bonded together, over and through the mask, such that the bonding material is applied to one or more selected regions of the recently deposited layer of porous material; and repeating the foregoing three steps a selected number of times to produce a selected number of successive layers, said bonding material causing each of said successive layers to become bonded to an adjacent layer. Any unbonded porous material that is not at the selected regions is easily removed. The mask may be an open stencil mask, or a screen mask. If open stencil masks are used, there may be more than one mask for a single layer of porous material. Successive masks may be positioned by a continuous sheet, a rotating disk, or individually, such as by a robot. The porous material may be metallic or ceramic or plastic, and it may be loose powder or loosely bonded powder. The bonding material may be applied as droplets or a jet. Droplets may be applied by sonic or ultrasonic atomizer, through a nozzle, a simple orifice, or by an electrostatic arrangement, such as in electrostatic painting. The mask may be positioned in contact with the powder material or spaced away therefrom.

Claims

1. A process for making a component comprising the steps of:

a. depositing a layer of a porous material;

b. positioning a mask near to said deposited layer of porous material;

c. applying a bonding material that will cause any contacted portions of said porous material to become bonded together, over and through said mask, such that said bonding material is applied to one or more selected regions of said layer of porous material; and

d. repeating steps (a), (b) and (c) to produce successive layers, said bonding material causing each of said successive layers to become bonded to an adjacent layer.

2. The process of claim 1, further comprising the step of removing any unbonded porous material which is not at said one or more selected regions to provide the component.

3. The process of claim 1, said mask comprising figure regions that are permeable to said bonding material and ground regions that are impervious to said bonding material, said step of applying a bonding material comprising the step of applying said bonding material over both said figure and ground regions of said mask.

4. The process of claim 1, said step of depositing a layer of porous material comprising the step of depositing a layer of loose powder.

5. The process of claim 1, said step of depositing a layer of porous material comprising the step of depositing a body of loosely bound powder.

6. The process of claim 1, said step of applying bonding material comprising the step of spraying droplets of bonding material at said mask.

7. The process of claim 1, said step of applying bonding material comprising the step of directing a jet of droplets of bonding material at said mask.

8. The process of claim 1, said step of applying bonding material comprising the step of directing a jet of continuous fluid bonding material at said mask.

9. The process of claim 6, said step of spraying comprising the step of spraying droplets in a conical pattern.

10. The process of claim 1, said step of positioning said mask comprising the step of contacting said deposited layer of porous material with said mask.

11. The process of claim 1, said step of positioning said mask comprising the step of spacing said mask away from said layer of porous material.

12. The process of claim 1, said step of positioning comprising the step of moving a mask to a stationary bonding material application station.

13. The process of claim 1, said step of positioning comprising the step of moving said layer of porous material to a stationary bonding material application station.

14. The process of claim 12, said step of moving said mask comprising the step of rotating a disk upon which said mask resides.

15. The process of claim 12, said step of moving said mask comprising the step of indexing a sheet upon which said mask resides.

16. The process of claim 12, said step of moving said mask comprising the step of positioning a frame in which said mask resides.

17. The process of claim 1, said step of positioning a mask comprising the step of positioning a plurality of stencil masks for a single layer of porous material.

18. The process of claim 1, said step of positioning a mask comprising the step of positioning a stencil mask having a completely open figure region.

19. The process of claim 1, said step of positioning a mask comprising the step of positioning a screen mask.

20. The process of claim 1, said step of applying bonding material comprising the step of applying an electric charge to said bonding material before it contacts said porous material.

21. The process of claim 20, said step of applying bonding material further comprising the step of establishing an electric field that attracts any said charged bonding material toward said porous material.

22. The process of claim 21, said step of establishing an electromagnetic field comprising the step of electrically coupling said porous material to a voltage source chosen to attract any said charged bonding material.

23. The process of claim 21, said step of establishing an electric field comprising the step of providing an electrically conductive body adjacent said porous material, on the side of said porous material distant from said recently deposited layer, and electromagnetically coupling said conductive body to a voltage source chosen to attract any said charged bonding material.

24. An apparatus for making a component, said apparatus comprising:

a. means for depositing successive layers of a porous material;

b. means for positioning a mask, having figure and ground regions, adjacent each of said successive layers of said porous material; and

c. means for applying through a positioned mask, to one or more selected regions of each successive layer of porous material, after each successive layer has been deposited, a bonding material that will cause any porous material to which it is applied to become bonded at said one or more selected regions.

25. An apparatus for making a component, said apparatus comprising:

a. a porous material successive layer depositor;

b. a mask positioner, arranged to position a mask having figure and ground regions, near to each of any successive layers of said porous material deposited by said layer depositor; and

c. a bonding material applicator, arranged to apply, through a positioned mask, to one or more selected regions of each successive layer of porous material, after each of any such successive layers has been deposited, a bonding material that will cause the porous material to become bonded at said one or more selected regions.

26. The apparatus of claim 25, said mask positioner comprising a mask sheet advancer that advances a stretch of a continuous mask sheet adjacent said layer depositor.

27. The apparatus of claim 26, said sheet advancer comprising a sheet indexer.

28. The apparatus of claim 25, said mask positioner comprising a disk drive that advances a sector of a mask disk adjacent said layer depositor.

29. The apparatus of claim 26, said mask positioner comprising means for positioning said mask a distance spaced from any said deposited porous material.

30. The apparatus of claim 25, said bonding material applicator comprising a fluid jet applicator.

31. The apparatus of claim 25, said bonding material applicator comprising a fluid spray applicator.

32. The apparatus of claim 25, said bonding material applicator comprising a sonic atomizer.

33. The apparatus of claim 25, said bonding material applicator comprising an ultrasonic atomizer.

34. The apparatus of claim 25, said bonding material applicator comprising air atomizer.

35. The apparatus of claim 25, said bonding material applicator comprising a nozzle.

36. The apparatus of claim 25, said bonding material applicator comprising an orifice.

37. The apparatus of claim 25, said mask positioner comprising a mask locator.

38. The apparatus of claim 25, said bonding material applicator comprising an electrostatic applicator that applies a charge to any bonding material applied thereby.

39. The apparatus of claim 38, further comprising a charge applicator that maintains an electric field that attracts any charged bonding material toward any deposited porous material.

40. The apparatus of claim 34, said air atomizer cmprising a venturi type atomizer.