PNEUMATIC JETTING OF METAL FOR ADDITIVE MANUFACTURING

• US 20170252808A1
• Filed: 03/03/2017
• Published: 09/07/2017
• Est. Priority Date: 03/03/2016
• Status: Active Grant

• Current Assignee: Desktop Metal, Inc.
• Original Assignee: Desktop Metal, Inc.
• Inventors: Myerberg, Jonah Samuel, Natchurivalapil Rappai James, Toshana Krishna, Sachs, Emanuel Michael, Hoisington, Paul A., Li, Kevin Michael
• Granted Patent: US 10,639,716 B2
• Time in Patent Office: Days
• CPC Class Codes: B22F 10/22 Direct deposition of molten metal
• CPC Class Codes: B22F 10/32 of the atmosphere, e.g. composition or pressure in a building chamber
• CPC Class Codes: B22F 12/10 Auxiliary heating means
• CPC Class Codes: B22F 12/22 Driving means
• CPC Class Codes: B22F 12/53 Nozzles
• CPC Class Codes: B22F 2009/0892 casting nozzle; controlling metal stream in or after the casting nozzle
• CPC Class Codes: B22F 2202/05 Use of magnetic field
• CPC Class Codes: B22F 2203/13 pressure
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/003 Apparatus, e.g. furnaces in general F27B
• CPC Class Codes: B22F 3/115 by spraying molten metal, i.e. spray sintering, spray casting
• 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 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

Devices, systems, and methods are directed to the pneumatic ejection of liquid metal from a nozzle moving along a controlled three-dimensional pattern to fabricate a three-dimensional object through additive manufacturing. The metal is movable into the nozzle as a valve is actuated to control movement of pressurized gas into the nozzle. Such movement of metal into the valve as pressurized gas is being moved into the nozzle to create an ejection force on liquid metal in the nozzle can reduce or eliminate the need to replenish a supply of the metal in the nozzle and, therefore can facilitate continuous or substantially continuous liquid metal ejection for the fabrication of parts.

Claims

1. An additive manufacturing system, the system comprising:

a nozzle defining a volume and a discharge orifice in fluid communication with one another;

a source of a pressurized gas;

a valve actuatable to control fluid communication between the source of pressurized gas and the volume of the nozzle; and

a media supply in fluid communication with the volume of the nozzle, wherein metal from the media supply is movable into the volume of the nozzle as the valve is actuated to eject, under pneumatic force of the pressurized gas in the nozzle, a liquid form of the metal from the discharge orifice along a controlled three-dimensional pattern associated with fabrication of a three-dimensional object.

2. The system of claim 1, wherein metal from the media supply is movable into the volume while the valve is positioned to interrupt fluid communication between the discharge orifice of the nozzle and the source of the pressurized gas.

3. The system of claim 1, wherein the nozzle further defines a first port and a second port, the first port and the second port spaced apart from one another along the volume of the nozzle, the actuation of the valve controlling movement of the pressurized gas into the volume of the nozzle through the first port.

4. The system of claim 3, wherein the first port and the second port are substantially axially aligned with one another along the volume of the nozzle.

5. The system of claim 3, wherein the media supply is in fluid communication with the volume of the nozzle through the second port.

6. The system of claim 3, wherein the second port is vented to the atmosphere.

7. The system of claim 3, wherein the second port is vented to a vacuum.

8. The system of claim 3, further including a media drain in fluid communication with the volume of the nozzle, wherein the metal from the media supply is movable from the volume of the nozzle to the media drain.

9. The system of claim 8, wherein the discharge orifice and the first port are positioned relative to one another such that metal moving from the media supply to the media drain moves between the discharge orifice and the first port.

10. The system of claim 1, further comprising a heater arranged to heat at least a portion of the nozzle adjacent to the discharge orifice.

11. The system of claim 10, wherein the heater is one or more of a resistance heater and an induction heater.

12. The system of claim 10, wherein the metal supply is movable into a portion of the volume adjacent to the discharge orifice.

13. The system of claim 1, further comprising an inert gas curtain disposed at least partially around the discharge orifice.

14. A method of additive manufacturing, the method comprising:

directing a metal into a volume defined by a nozzle;

moving a discharge orifice and a build plate relative to one another along a controlled three-dimensional pattern, the discharge orifice defined by the nozzle and in fluid communication with the volume; and

based at least in part on a position of the discharge orifice along the controlled three-dimensional pattern, selectively delivering pulses of pressurized gas into the volume to eject a liquid form of the metal from the discharge orifice to form a three-dimensional object on the build plate, wherein the metal is directed into the volume defined by the nozzle as the pulses of pressurized gas are selectively delivered into the volume.

15. The method of claim 14, wherein selectively delivering pulses of pressurized gas into the volume to eject the liquid form of the metal includes ejecting the liquid form of the metal from the discharge orifice in a direction having a vertical component opposite a direction of gravity.

16. The method of claim 14, further comprising heating the nozzle at least along a portion of the nozzle defining the discharge orifice.

17. The method of claim 14, wherein directing the metal into the volume defined by the nozzle includes directing a solid form of the metal into the nozzle.

18. The method of claim 14, further comprising venting the pressurized gas from the volume of the nozzle through a port defined by the nozzle and in fluid communication with the atmosphere or a vacuum.

19. The method of claim 18, wherein directing the metal into the volume includes moving the metal into the volume through the port.

20. The method of claim 14, wherein the pressurized gas is inert with respect to the metal.

21. The method of claim 14, further comprising draining the liquid metal from the volume of the nozzle as the pulses of pressurized gas are selectively delivered into the volume.

22. The method of claim 14, wherein the liquid form of the metal is ejected into one or more of an inert atmosphere and a vacuum housed within a build chamber during fabrication of the three-dimensional object.

23. The method of claim 14, further comprising adjusting the discharge orifice to control a meniscus of the liquid form of the metal at the discharge orifice.