SELECTIVE PNEUMATIC JETTING OF METAL FOR ADDITIVE MANUFACTURING

• US 20170252811A1
• Filed: 03/03/2017
• Published: 09/07/2017
• Est. Priority Date: 03/03/2016
• Status: Abandoned Application

• 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, Fontana, Richard Remo
• Application Number:
  US15/449,607
• Publication Number:
  US 20170252811A1
• 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 switching between pneumatically actuated ejection and electrically actuated ejection of liquid metal from a nozzle moving along a controlled three-dimensional pattern to fabricate a three-dimensional object. Electrically actuated ejection can be useful, for example, for delivering discrete droplets in areas of the object requiring a high degree of accuracy. Pneumatic ejection can be useful, for example, for delivering a stream of liquid metal from the nozzle to provide liquid metal rapidly to areas of the object that require less accuracy (e.g., an inner portion of the object). Accordingly, switching between pneumatically actuated ejection and electrically actuated ejection can facilitate accurate and rapid production of parts through additive manufacturing.

Claims

1. 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;

based at least in part on a position of the discharge orifice along the controlled three-dimensional pattern, selectively switching between pneumatically actuated ejection and electrically actuated ejection of a liquid form of the metal from the discharge orifice; and

ejecting the liquid form of the metal from the discharge orifice according to the selected one of the pneumatically actuated ejection and the electrically actuated ejection to form at least a portion of a three-dimensional object.

2. The method of claim 1, wherein, upon selection of the pneumatically actuated ejection, ejecting the liquid form of the metal from the discharge orifice includes ejecting a substantially constant stream of the liquid form of the metal from the discharge orifice.

3. The method of claim 1, wherein, upon selection of the electrically actuated ejection, ejecting the liquid form of the metal from the discharge orifice includes controlling a pulsed electrical current.

4. The method of claim 3, wherein droplets of the liquid form of the metal are ejected from the discharge orifice in response to the pulsed electrical current.

5. The method of claim 1, wherein selectively switching between pneumatically actuated ejection and electrically actuated ejection includes selecting the electrically actuated ejection along a border of the controlled three-dimensional pattern and selecting the pneumatically actuated ejection along an excursion away from the border of the controlled three-dimensional pattern.

6. The method of claim 1, wherein ejecting liquid metal from the discharge orifice according to pneumatically actuated ejection includes delivering pressurized air to the volume.

7. The method of claim 6, further comprising venting the pressurized air to one or more of the atmosphere and a vacuum as the liquid form of the metal is ejected through the discharge orifice.

8. The method of claim 1, wherein ejecting liquid metal from the discharge orifice according to the electrically actuated ejection includes delivering an electric current into the liquid form of the metal.

9. The method of claim 8, wherein the electric current results in a magnetohydrodynamic force exerted on the liquid form of the metal.

10. The method of claim 8, wherein the electric current results in an electrohydrodynamic force exerted on the liquid form of the metal.

11. The method of claim 1, wherein ejecting liquid metal from the discharge orifice according to the electrically actuated ejection includes delivering an electric current to an actuator in mechanical communication with the liquid form of the metal and movable in response to the electric current to exert a mechanical force on the liquid form of the metal to eject the liquid form of the metal from the discharge orifice.

12. The method of claim 11, wherein the actuator includes a piezoelectric element.

13. The method of claim 1, further comprising heating the metal in the volume at least along a portion of the volume defining the discharge orifice.

14. The method of claim 1, wherein directing the metal into the volume includes moving the metal into the volume as the liquid form of the metal is discharged from the orifice.

15. The method of claim 1, further comprising draining the liquid form of the metal from the volume, through a media drain separate from the discharge orifice, as the liquid form of the metal is discharged from the orifice.

16. An additive manufacturing system, the system comprising:

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

a build plate spaced apart from the discharge orifice of the nozzle;

a source of a pressurized gas;

an electrical power source;

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

a robotic system mechanically coupled to the nozzle, the robotic system movable to move the discharge orifice and the build plate relative to one another in three-dimensions; and

a controller in electrical communication with the valve, the electrical power source, and the robotic system, the controller configured to actuate the robotic system to move the discharge orifice and the build plate relative to one another along a controlled three-dimensional pattern, and the controller further configured to activate the valve and the power source, based at least in part on a position of the discharge orifice along the controlled three-dimensional pattern, to selectively switch between pneumatically actuated ejection and electrically actuated ejection of a liquid form of a metal from the discharge orifice to form a three-dimensional object on the build plate.

17. The system of claim 16, wherein selectively switching between pneumatically actuated ejection and electrically actuated ejection includes selecting the electrically actuated ejection along a border of the controlled three-dimensional pattern and selecting the pneumatically actuated ejection along an excursion away from the border of the controlled three-dimensional pattern.

18. The system of claim 16, wherein, upon selection of the pneumatically actuated ejection, the controller actuates the valve to establish fluid communication between the source of the pressurized gas and the volume.

19. The system of claim 16, wherein, upon selection of the electrically actuated ejection, the controller actuates the power source to deliver electric current to the volume.

20. The system of claim 19, wherein the controller actuates the power source to deliver a pulsed electric current to the volume.