Device and arrangement for producing a three-dimensional object

• US 20040026807A1
• Filed: 08/13/2003
• Published: 02/12/2004
• Est. Priority Date: 04/27/2000
• Status: Active Grant

• Current Assignee: Arcam Ab (Danaher Corporation)
• Original Assignee: Arcam Ab (Danaher Corporation)
• Inventors: Andersson, Lars-Erik, Larsson, Morgan
• Granted Patent: US 7,537,722 B2
• Time in Patent Office: Days
• US Class Current: 264/40.1
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 12/30 Platforms or substrates
• CPC Class Codes: B22F 12/52 Hoppers
• CPC Class Codes: B22F 12/90 Means for process control, e.g. cameras or sensors
• CPC Class Codes: B22F 3/004 Filling molds with powder feeding material to presses in general B30B15/302
• CPC Class Codes: B29C 2035/0838 using laser
• CPC Class Codes: B29C 2035/0877 using electron radiation, e.g. beta-rays
• CPC Class Codes: B29C 35/0288 Controlling heating or curing of polymers during moulding, e.g. by measuring temperatures or properties of the polymer and regulating the process controlling or regulating chemical, physical or physico- chemical processes in general B01J19/0006
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• 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: Y02P 10/25 Process efficiency

Abstract

A device for manufacturing a three-dimensional product, which device comprises a work table on which said three-dimensional product is to be built, a powder dispenser which is arranged to lay down a thin layer of powder on the work table for the formation of a powder bed, a ray gun for giving off energy to the powder whereby fusion of the powder takes place, members for controlling of the beam released by the ray gun across said powder bed for the formation of a cross section of said three-dimensional product through fusion of parts of said powder bed, and a controlling computer in which information about successive cross sections of the three-dimensional product is stored, which cross sections build the three-dimensional product, the controlling computer intended to control said members for guiding the ray gun across the powder bed according to a running schedule forming a cross section of said three-dimensional body, whereby said three-dimensional product is formed by successive fusion of successively formed cross sections from powder layers successively laid down by the powder dispenser.

Claims

1. A device for manufacturing a three-dimensional product, which device comprises a work table on which said three-dimensional product is to be built, a powder dispenser which is arranged to lay down a thin layer of powder on the work table for the formation of a powder bed, a ray gun for giving off energy to the powder whereby fusion of the powder takes place, members for controlling the beam released by the ray gun across said powder bed for the formation of a cross section of said three-dimensional product through fusion of parts of said powder bed, and a controlling computer in which information about successive cross sections of the three-dimensional product is stored, which cross sections build the three-dimensional product, the controlling computer intended to control said members for guiding the ray gun across the powder bed according to a running schedule forming a cross section of said three-dimensional body, whereby said three-dimensional product is formed by successive fusion of successively formed cross sections from powder layers successively laid down by the powder dispenser characterised by

that the device further comprises members for sensing surface characteristics of a surface layer at the powder bed.

2. A device according to claim 1, characterised in that said surface characteristics is constituted by the temperature distribution of a surface layer at the powder bed.

3. A device according to claim 1 or 2, characterised in that said surface characteristics is constituted by the surface smoothness of a surface layer at the powder bed.

4. A device according to any of claims 1-3, characterised in that said member for sensing of the temperature distribution is arranged to communicate information about the temperature distribution across the surface layer of the powder bed to said controlling computer, whereby said information about temperature distribution is intended to affect said running schedule for the ray gun.

5. Device according to claim 4, characterised in that said information about the temperature distribution of the surface layer of the powder bed is utilised to increase the energy delivery within areas of the surface layer of the powder bed with too low temperature and decrease energy delivery within areas with too high temperature whereby a more even working temperature of the cross sections is obtained.

6. Device according to claim 4 or 5, characterised in that said information about the temperature distribution is arranged to control the energy delivery from the ray gun to the powder bed at fused areas within the presently uppermost powder layer, so that the maximum temperature after fusion at these areas is within a limited range.

7. Device according to any of claims 4-6, characterised in that said information about the temperature distribution is arranged to control the energy delivery from the ray gun to the powder bed on the one hand fused at areas within the presently uppermost powder layer and on the other hand to be united with areas in a subsequent layer, so that the minimum temperature after fusion at these areas does not fall below a predetermined limit.

8. Device according to any of claims 4-6, characterised in that said information about the temperature distribution is arranged to control the energy delivery from the ray gun to the powder bed at areas on the one hand fused within the presently uppermost powder layer so that the minimum temperature after fusion at these areas does not fall below a predetermined limit.

9. A device according to any of claims 4-8, characterised in that said information about the temperature distribution is arranged to control the energy delivery from the ray gun to the powder bed at areas within the uppermost layer of the powder bed that are not so that the temperature within these areas does not fall below a second predetermined limit.

10. A device according to any of claims 4-9, characterised in that said information about the temperature distribution is arranged to be used for calibrating said member for controlling the ray gun.

11. A device according to any of the preceding claims, characterised in that said member for sensing surface characteristics of a surface layer at the powder bed is constituted by a camera.

12. A device according to claim 11, characterised in that the product bed is situated in a closed chamber, that the closed chamber exhibits a transparent window, and that the camera is arranged to record said surface characteristic of the powder bed through this window.

13. A device according to claim 12, characterised in that the transparent window is protected by a film, that said film is feedingly arranged along the window whereby new film is fed whereby the transparency through the film and the window is maintained.

14. A device according to any of the preceding claims, characterised in that the ray gun is constituted by an electron gun, and that the powder bed and the electron gun are enclosed within a vacuum chamber.

20. A method according to claim 10, characterised in that areas with a too low cooling temperature is reheated.

15. Method for the manufacturing of three-dimensional bodies through successive fusion of parts of a powder bed, which parts correspond to successive cross sections of the three-dimensional body, which method comprises the following method steps:

laying down a powder layer on a work table,

supplying energy from a ray gun according to a predetermined running schedule for the powder layer,

fusion of the area of the powder layer selected according to said running schedule for the formation of a cross section of said three-dimensional body, and

formation of a three-dimensional body through successive fusion of successively formed cross sections from powder layers successively laid down

characterised in that the method further comprises sensing of surface characteristics of a surface layer situated at the powdered.

16. A method according to claim 15, characterised in that said sensed surface characteristics comprise measuring of the surface smoothness of a surface layer at the powder bed.

17. A method according to claim 15 or 16, characterised in that said sensed surface characteristics comprise measuring of the temperature distribution of a surface layer at the powder bed.

18. Method according to claim 17, characterised in that the sensed temperature distribution is utilised to calibrate the energy supply to the ray gun for the achievement of the correct melting temperature.

19. A method according to any of claims 17 or 18, characterised in that the sensed temperature distribution is utilised to achieve a correct cooling temperature by modifying said running schedule.

21. A method according to claims 19 or 20, characterised in that upon detection of an area with a too high cooling temperature, the running schedule is modified so that the build-up rate within this area is decreased.

22. A method according to any of claims 17-21, characterised in that the bed temperature is detected and that the bed is heated if the detected temperature falls below a predetermined limit.

23. Method according to any of the claims 17-22, characterised in that the sensed temperature distribution is utilised to calibrate the members arranged at the ray gun for the X-Y deflection of the beam.

24. A method according to any of claims 16-23, characterised in that the following method steps are taken upon detecting a surface irregularity:

the coordinates of the surface irregularity are registered and

the beam generated by the ray gun is guided to said coordinates, where-after the surface irregularity is melted.

25. A device for the manufacturing of a three-dimensional product through energy transfer from an energy source to a product raw material, which device comprises a work table on which said three-dimensional product is to be built, a dispenser arranged to lay down a thin layer of product raw material on the work table for the formation of a product bed, a member for giving off energy to selected areas of the surface of the product bed, whereby a phase transition of the product raw material is allowed for the formation of a solid cross section within said area, and a controlling computer handling a memory in which information about successive cross sections of the three-dimensional product is stored, which cross sections constitute the three-dimensional product, where the controlling computer is intended to control said member for releasing energy so that energy is supplied to said selected areas, whereby said three-dimensional product is formed through successive bonding of cross sections, successively formed from layers of product raw materials laid down by the powder dispenser characterised in that the device further comprises members for sensing of surface characteristics of a surface layer at the powder bed.

26. A device according to claim 25, characterised in that said surface characteristics is constituted by the temperature distribution of a surface layer at the product bed.

27. A device according to claim 25 or 26, characterised in that said surface characteristics is constituted by the surface smoothness of a surface layer at the product bed.

28. A device according to any of claims 25-27, characterised in that said member for sensing of the temperature distribution is arranged to communicate information about the temperature distribution across the surface layer of the product bed to said controlling computer, whereby said controlling computer utilises this information for controlling said member for delivering energy to the product bed.

29. A device according to claim 28, characterised in that said information about the temperature distribution is arranged to be used for measurement calibrating of said member for delivering energy to the product bed.

30. A device according to any of the claims 25-29, characterised in that said member for sensing surface characteristics is constituted by a camera.

31. A device according to claim 30, characterised in that the product bed is situated in a closed chamber, that the closed chamber exhibits a transparent window, and that the camera is arranged to record said surface characteristic of the powder bed through this window.

32. A device according to claim 31, characterised in that the transparent window is protected by a film, and that said film is feedingly arranged along the window whereby new film is fed whereby the transparency through the film and the window is maintained.