Powder pre-processing for additive manufacturing

• US 9,561,542 B2
• Filed: 11/06/2012
• Issued: 02/07/2017
• Est. Priority Date: 11/06/2012
• Status: Active Grant

• Current Assignee: Arcam Ab (Danaher Corporation)
• Original Assignee: Arcam Ab (Danaher Corporation)
• Inventors: Ackelid, Ulf
• Primary Examiner(s): Roe, Jessee
• Assistant Examiner(s): JONES, JEREMY CONRAD
• Application Number:
  US14/439,209
• Publication Number:
  US 20150290710A1
• Time in Patent Office: 1,554 Days
• US Class Current: 1/1
• CPC Class Codes: B22F 1/142 Thermal or thermo-mechanical treatment
• 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 10/34 of powder characteristics, e.g. density, oxidation or flowability
• CPC Class Codes: B22F 10/362 for preheating
• CPC Class Codes: B22F 12/13 to preheat the material
• CPC Class Codes: B22F 12/52 Hoppers
• CPC Class Codes: B22F 12/55 Two or more means for feeding material
• CPC Class Codes: B28B 1/001 Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material selective deposition modelling of metallic powder B22F10/00; rapid manufacturing of 3D objects in general and in particular of plastics B29C64/00
• CPC Class Codes: B28B 17/026 Conditioning ceramic materials
• CPC Class Codes: B29B 13/065 of powder or pellets
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B29C 64/255 Enclosures for the building material, e.g. powder containers
• CPC Class Codes: B29C 64/295 Heating elements
• CPC Class Codes: B29C 64/314 Preparation
• CPC Class Codes: B29C 64/364 Conditioning of environment
• CPC Class Codes: B29K 2105/251 Particles, powder or granules expandable particles B29K2105/046
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: B33Y 40/10 Pre-treatment
• CPC Class Codes: Y02P 10/25 : Process efficiency

Abstract

The present invention relates to a method for removing moisture from powder to be used in an additive manufacturing process for forming a three-dimensional article through successive fusion of parts of at least one layer of a powder bed provided on a work table, which parts corresponds to successive cross sections of the three-dimensional article, characterized in that said method comprising the steps of: providing at least a first powder tank and at least at least a second powder tank, providing a predetermined amount of powder on a movable table inside said first powder tank, heating the top surface of the powder in said first powder tank to a predetermined temperature interval for removing moisture from said powder, raising said movable table a predetermined distance, moving a predetermined thickness of the powder material from said first powder tank to said second powder tank.

Claims

1. A method for removing moisture from powder to be used in an additive manufacturing process for forming a three-dimensional article through successive fusion of parts of at least one layer of a powder bed provided on a work table located within a build tank, which parts corresponds to successive cross sections of the three-dimensional article, said method comprising the steps of:

providing at least a first powder tank and at least a second powder tank, providing a predetermined amount of powder on a movable table inside said first powder tank,

heating the top surface of the powder in said first powder tank to a predetermined temperature for removing moisture from said powder,

raising said movable table a predetermined distance,

moving a predetermined thickness of the powder material from said first powder tank to said second powder tank, wherein said first powder tank is said build tank for building said three dimensional article,

continuing said heating and moving of dried powder from the build tank to the second powder tank until the predetermined amount of powder is moved from the build tank to the second powder tank.

2. The method according to claim 1, wherein said movable table is said work table.

3. The method according to claim 1, further comprising the step of providing said first and second powder tank inside an enclosable chamber.

4. The method according to claim 3, wherein said enclosable chamber is a vacuum chamber.

5. The method according to claim 1, wherein said predetermined temperature is less than a reaction temperature in which the moisture is starting to react with the powder material.

6. The method according to claim 1, wherein said temperature is less than a sintering temperature in which powder particles in said powder is starting to sinter together.

7. The method according to claim 1, further comprising the step of providing a supplementary heating device for heating the top surface of the powder material from above.

8. The method according to claim 1, wherein the fusing of the powder material and heating of the top surface of the powder material for removing moisture are performed by a shared high energy beam source.

9. The method according to claim 8, wherein said supplementary heating device is at least one of a laser or an infrared source.

10. The method according to claim 8, wherein said high energy beam source is an electron beam.

11. The method according to claim 4, further comprising the step of starting said heating of said top surface of said powder material as soon as vacuum conditions in said vacuum chamber are established.