Method and apparatus for producing a three-dimensional object

• US 5,647,931 A
• Filed: 08/22/1995
• Issued: 07/15/1997
• Est. Priority Date: 01/11/1994
• Status: Expired due to Fees

• Current Assignee: EOS GmbH Electro Optical Systems
• Original Assignee: EOS GmbH Electro Optical Systems
• Inventors: Retallick, David, Langer, Hans J.
• Primary Examiner(s): SELLS, JAMES D
• Application Number:
  US08/507,516
• Time in Patent Office: 693 Days
• Field of Search: 156/272.2, 156/273.3, 156/273.5, 156/275.5, 156/290, 156/329.6, 156/379.8, 156/73.6, 156/381, 156/382, 264/69, 264/109, 264/123, 264/308, 264/401, 264/402, 264/85, 264/125, 222/185.1, 222/368, 222/410, 222/413, 222/414, 425/174.4
• US Class Current: 156/73.6
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/32 of the atmosphere, e.g. composition or pressure in a building chamber
• CPC Class Codes: B22F 12/13 to preheat the material
• CPC Class Codes: B22F 12/49 Scanners
• CPC Class Codes: B22F 12/50 Means for feeding of material, e.g. heads
• CPC Class Codes: B22F 12/55 Two or more means for feeding material
• CPC Class Codes: B22F 12/57 Metering means
• CPC Class Codes: B22F 12/67 Blades
• CPC Class Codes: B22F 12/70 Gas flow means
• CPC Class Codes: B22F 2202/01 Use of vibrations
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/004 Filling molds with powder feeding material to presses in general B30B15/302
• CPC Class Codes: B29C 2791/005 Using a particular environment, e.g. sterile fluids other than air
• CPC Class Codes: B29C 31/08 of preforms to be moulded, e.g. tablets, fibre reinforced preforms, extruded ribbons, tubes or profiles; Manipulating means specially adapted for feeding preforms, e.g. supports conveyors B29C31/066, B29C37/001, B29C43/085 take precedence
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

In a method and an apparatus for producing three-dimensional objects by layerwise solidification of a material the problem is encountered that, in particular when using powdery or pasty material, a material layer having an exactly adjusted thickness can not be generated in a sufficiently fast manner. In order to solve this problem, it is proposed to scrape the material by means of a vibrating wiper member (21, 22) when applying the material or to provide a movable container (13) used for applying the material with such wiper members (21, 22) at the lower side thereof.

Claims

1. A method of producing a three-dimensional object layer by layer on a support using a powdery material which can be solidified by irradiation with electromagnetic radiation, said method comprising carrying out the following steps for each layer:

applying a layer of said material to said support or to a preceding layer;

wiping said layer by moving a wiper member across said support to obtain a predetermined thickness of said material,

vibrating said wiper member while moving it across said support to accelerate the formation of said layer having said predetermined thickness and to enhance surface smoothness and compactness of said layer,

striking said layer with a beam of electromagnetic radiation at those portions of said layer which correspond to said object, thereby fusing said material at said portions of said layer,

whereby said step of applying comprises charging a predetermined amount of said material into a container, said container carrying said wiper member, moving said container across said support and vibrating said container while moving it for simultaneously applying and wiping said material.

2. The method of claim 1 comprising subjecting said wiper member to a vibration in a direction transverse to said wiping direction and parallel to said support or said layer.

3. The method of claim 1 comprising vibrating said wiper member with a vibration having a frequency of about 50 to 500 Hertz and an amplitude of about 0.1 to 2 mm.

4. The method of claim 1 comprising vibrating said wiper member with a vibration having a frequency of about 100 to 200 Hertz and an amplitude of about 0.5 to 1 mm.

5. The method of claim 1 comprising applying said material directly ahead of said wiper member while wiping said layer.

6. The method of claim 1 comprising changing said wiping direction after applying a layer.

7. The method of claim 1 comprising applying said material to a level-adjustable support, lowering said support by an amount corresponding to the thickness of the following layer after fusing the preceding layer or holding said support stationary for applying and fusing a second layer.

8. The method of claim 1 comprising producing an inert gas atmosphere and carrying out said applying, wiping, vibrating and fusing steps under said inert gas atmosphere.

9. A method of producing a three-dimensional object layer by layer on a support using a material which can be solidified by irradiating with electromagnetic radiation, said method comprising carrying out the following steps for each layer:

applying a layer of said material to said support or to a preceding layer,

wiping said layer by moving a wiper member across said support to obtain a predetermined thickness of said material,

vibrating said wiper member while moving it across said support by subjecting said wiper member to a vibration in a direction transverse to said wiping direction and parallel to said support or said layer so as to accelerate the formation of said layer having said predetermined thickness and to enhance surface smoothness and compactness of said layer,

striking said layer with a beam of electromagnetic radiation at those portions of said layer which correspond to said object, thereby fusing said material at said portions of said layer.

10. The method of claim 9, further comprising:

generating an inert gas atmosphere in a space surrounding said support, and

carrying out said applying, wiping and striking steps within said inert gas atmosphere.

11. Apparatus for producing a three-dimensional object layer by layer using a powdery material which can be solidified by irradiating it with electromagnetic radiation, said apparatus comprising:

a support means,

means for applying a layer of said material to said support means,

scanning means for irradiating said layer at those portions thereof corresponding to said object,

said applying means comprising a container means disposed above said support means, said container means receiving said material and having a lower side facing said support means,

drive means for moving said container means across said support means substantially parallel thereto,

wiper means for smoothing said layer to a predetermined thickness, said wiper means being disposed at said lower side of said container means and being fastened to said container means, and

vibrating means for vibrating said container means when moving said container means across said support means.

12. The apparatus of claim 11, said container means being formed as a trough extending transversely across said support means, said trough having an upper opening for charging material into said trough and a lower opening for applying said material.

13. The apparatus of claim 12, said trough having a substantially funnel-shaped cross-section.

14. The apparatus of claim 12, said lower opening being formed as a slit extending along said trough.

15. The apparatus of claim 12 comprising two wiper members, one wiper member being arranged in moving direction of said container means ahead of said lower opening and the other wiper member being arranged in moving direction of said container means behind said lower opening.

16. The apparatus of claim 15, said wiper members being formed by edges of said trough at both sides of said slit.

17. The apparatus of claim 11, said drive means comprising means for moving said container means in a first direction across said support means for applying a first layer and wiping said layer by means of said wiper means, and for moving said container after scanning said first layer in a second direction substantially opposite to said first direction for applying and wiping a following layer.

18. The apparatus of claim 11, said drive means comprising means for moving said container means into an end position after applying and wiping said material.

19. The apparatus of claim 18 comprising reservoir means for said material and feeding means for feeding a predetermined amount of said material from reservoir means into said container means, if said container means is in said end position.

20. The apparatus of claim 19, said feeding means being formed as a metering means, preferably a notched drum, arranged between said reservoir means and said container means when said container means is in said end position.

21. The apparatus of claim 19 comprising a corresponding end position with associated reservoir means and feeding means at both sides of said support means in moving direction of said container means.

22. The apparatus in claim 11, said vibrating means comprising an oscillating means vibrating said container means in a direction transverse to the moving direction of said container means and parallel to said layer.

23. The apparatus of claim 22 comprising means for supporting said container means to be resilient in vibrating direction, said oscillating means acting upon said container means.

24. The apparatus of claim 11 comprising a housing which tightly surrounds said support means and said applying means, and an inert gas source for supplying inert gas into said housing.

25. The apparatus of claim 24, said inert gas source being formed as a membrane separation means for separating nitrogen from air.

26. The apparatus of claim 11, further comprising:

housing means tightly surrounding said support means and said applying means, and

an inert gas source for feeding inert gas into said housing.

27. The apparatus of claim 26, said inert gas source being formed as a membrane separation means for separating nitrogen from air.

28. Apparatus for producing a three-dimensional object layer by layer using a material which can be solidified by irradiating it with electromagnetic radiation, said apparatus comprising:

a support means,

means for applying a layer of said material to said support means,

scanning means for irradiating said layer at those portions thereof corresponding to said object,

said applying means comprising a container means disposed above said support means, said container means receiving said material and having a lower side facing said support means,

drive means for moving said container means across said support means substantially parallel thereto said drive means comprising means for moving said container means into an end position after applying and wiping said material,

wiper means smoothing said layer to a predetermined thickness, said wiper means being disposed at said lower side of said container means and being fastened to said container means, and

vibrating means for vibrating said container means when moving said container means across said support means, and

reservoir means for said material and feeding means for feeding a predetermined amount of said material from said reservoir means into said container means, if said container means is in said end position.

29. The apparatus of claim 28, said feeding means being formed as a metering means, preferably a notched drum, arranged between said reservoir means and said container means when said container means is in said end position.

30. The apparatus of claim 28 comprising a corresponding end position with associated reservoir means and feeding means at both sides of said support means in moving direction of said container means.

31. The apparatus of claim 28, said vibrating means comprising an oscillating means vibrating said container means in a direction transverse to the moving direction of said container means and parallel to said layer.

32. The apparatus of claim 31 comprising means for supporting said container means to be resilient in vibrating direction, said oscillating means acting upon said container means.

33. The apparatus of claim 28 comprising a housing which tightly surrounds said support means and said applying means, and an inert gas source for supplying inert gas into said housing.

34. The apparatus of claim 33, said inert gas source being formed as a membrane separation means for separating nitrogen from air.