Controlled environment for additive manufacturing

Patent metadata

Field	Value
Publication number	US-11980940-B2
Application number	US-202017438439-A
Country	US
Kind code	B2
Filing date	Mar 20, 2020
Priority date	Mar 22, 2019
Publication date	May 14, 2024
Grant date	May 14, 2024

Abstract

A controlled environment system for the additive manufacture of metal objects using magnetohydrodynamic jetting. A sealing plate is placed against an Péclet gap seal of a volume enclosure. A flow of inert gas is used to maintain a high-purity volume in the interior of the volume enclosure. A print head accesses the interior and delivers build material through a hole in the sealing plate. A build plate is movable relative to the sealing plate within the interior of the volume enclosure on which objects can be fabricated.

First claim

What is claimed:

1. A controlled environment system for the additive manufacture of metal objects using magnetohydrodynamic jetting, comprising:
a sealing plate;
a volume enclosure including a Péclet gap seal formed by a gap between the sealing plate and the volume enclosure, the gap at least partially defined by a gap dimension and a sealing length, wherein the Péclet gap seal includes a flow of inert gas through the gap from an external gas supply to maintain a high-purity atmosphere in an interior volume of the volume enclosure;
a print head configured to deliver build material through an opening in the sealing plate; and
a build platform within the interior volume of the volume enclosure movable relative to the sealing plate.

2. The controlled environment system of claim 1 wherein the Péclet gap seal includes a circumferential ledge parallel to the sealing plate.

3. The controlled environment system of claim 2 wherein the flow of inert gas originates within the interior of the volume enclosure and flows in a gap formed between the sealing plate and the circumferential ledge.

4. The controlled environment system of claim 2 wherein the Péclet gap seal includes an aerostatic element expelling the inert gas.

5. The controlled environment system of claim 4 wherein the aerostatic element includes a distributor formed from a porous media.

6. The controlled environment system of claim 5 wherein the expelling of the inert gas and a flow of inert gas from the volume enclosure together contribute to the flow of inert gas through the Péclet gap seal.

7. The controlled environment system of claim 5 wherein the Péclet gap seal is maintained by three primary contact pads providing a bearing between the volume enclosure and the sealing plate.

8. The controlled environmental system of claim 7 wherein the distributor is recessed from the sealing plate relative to the primary contact pads.

9. The controlled environmental system of claim 8 wherein the distributor is recessed from the sealing plate relative to the primary contact pads by a distance between and inclusive of 50 to 500 microns.

10. The controlled environment system of claim 1 wherein the build platform is movable relative to a print head via a shaft sealed with a Péclet gap seal between the shaft and the volume enclosure.

11. The controlled environment system of claim 10 further comprising a motion system disposed outside of the volume enclosure and configured to move the build platform relative to the print head.

12. The controlled environment system of claim 1 further comprising an amount of thermal insulation disposed on an exterior of the volume enclosure.

13. A method of controlling an environment for the additive manufacture of metal objects using magnetohydrodynamic jetting, comprising:
providing a sealing plate;
disposing a Péclet gap seal formed by a gap between the sealing plate and a volume enclosure, the gap at least partially defined by a gap dimension and a sealing length;
flowing an inert gas at the Péclet gap seal to maintain a high-purity atmosphere in an interior volume of the volume enclosure;
moving a build platform relative to the sealing plate within the interior volume of the volume enclosure; and
delivering a build material to the build plate through an opening in the sealing plate.

14. The method of claim 13 wherein the Péclet gap seal includes a circumferential ledge parallel to the sealing plate.

15. The method of claim 14 wherein the flow of inert gas originates within the interior of the volume enclosure and flows in a gap formed between the sealing plate and the circumferential ledge.

16. The method of claim 14 wherein the Péclet gap seal includes an aerostatic element expelling the inert gas.

17. The method of claim 16 wherein the aerostatic element includes a distributor formed from a porous media.

18. The method of claim 17 wherein the expelling of the inert gas and a flow of inert gas from the volume enclosure together contribute to the flow of inert gas through the Péclet gap seal.

19. The method of claim 17 wherein the Péclet gap seal is maintained by at least three primary contact pads providing a bearing between the volume enclosure and the sealing plate.

20. The method of claim 19 wherein the distributor is recessed from the sealing plate relative to the primary contact pads.

21. The method of claim 20 wherein the distributor is recessed from the sealing plate relative to the primary contact pads by a distance between and inclusive of 50 to 500 microns.

22. The method of claim 13 wherein the build platform is movable relative to a print head via a shaft sealed with a Péclet gap seal between the shaft and the volume enclosure.

23. The method of claim 22 further comprising the step of operating a motion system disposed outside of the volume enclosure to move the build platform relative to the print head.

24. The method of claim 13 wherein the volume enclosure has disposed on an exterior an amount of thermal insulation.

Assignees

• Desktop Metal Inc

Inventors

• Sachs Emanuel Michael
• Bell Julian
• Bandiera Nicholas Graham

Classifications

• B22F12/70 Primary

  Gas flow means · CPC title

• B22D23/003

  Moulding by spraying metal on a surface · CPC title

• B22F10/22 Primary

  Direct deposition of molten metal · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title