Additive fabrication of sinterable metallic parts via application of directed energy

Patent metadata

Field	Value
Publication number	US-12017405-B2
Application number	US-202318193505-A
Country	US
Kind code	B2
Filing date	Mar 30, 2023
Priority date	Mar 20, 2019
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

According to some aspects, techniques are provided for fabricating sinterable metallic parts through the application of directed energy to a build material. In particular, applying energy to a build material comprising a polymer mixed with a metal powder may cause the polymer to form a cohesive structure with the metal powder. As a result, the polymer acts as a “glue” to produce a metallic green part without local melting of the metal. The green part may subsequently be sintered to remove the polymer and produce a fully dense metal part. Optionally, a step of debinding may also be performed prior to, or simultaneously with, sintering.

First claim

What is claimed is:

1. A method of fabricating an object via additive fabrication, the method comprising:
depositing a metal powder into a build region of an additive fabrication device, the metal powder comprising metal particles and a polymer adhered to the metal particles, wherein the metal powder comprises particles of the polymer adhered to the metal particles,
wherein the metal particles are particles of stainless steel, carbon steel, copper, tool steel, or titanium, and have a diameter between 1 μm and 100 μm,
wherein the polymer comprises polyamide and a wax; and

directing, by the additive fabrication device, radiation from a laser onto the deposited metal powder to cause at least some of the polymer to melt and adhere to other portions of the polymer and/or the metal particles, without sintering the metal particles.

2. The method of claim 1 , wherein the polymer comprises polypropylene, polyethylene, and/or paraffin.

3. The method of claim 1 , further comprising fabricating a sinterable metallic part through repetition of the acts of depositing build material and directing energy onto the build material.

4. The method of claim 3 , further comprising sintering the sinterable metallic part in a furnace.

5. The method of claim 1 , wherein the radiation produced by the laser comprises visible light.

6. The method of claim 1 , wherein the metal powder further comprises one or more flow improvers.

7. The method of claim 1 , wherein the metal particles have a diameter between 1 μm and 50 μm.

8. The method of claim 7 , wherein the metal particles have a diameter between 5 μm and 25 μm.

9. The method of claim 1 , wherein the polymer comprises a polyolefin.

10. The method of claim 1 , wherein the wax is a polyethylene wax.

11. A method of fabricating an object via additive fabrication, the method comprising:
fabricating one or more sinterable metallic parts through repeated acts of:
depositing a metal powder into a build region of an additive fabrication device, the metal powder comprising metal particles and a polymer adhered to the metal particles, wherein the metal powder comprises particles of the polymer adhered to the metal particles, and wherein the polymer comprises polyamide and a polyethylene wax; and
directing, by the additive fabrication device, radiation from a laser onto selected regions of the deposited metal powder to cause at least some of the polymer to melt and adhere to other portions of the polymer and/or the metal particles, without sintering the metal particles; and

sintering the one or more sinterable metallic parts in a furnace.

12. The method of claim 11 , further comprising debinding the one or more sinterable metallic parts prior to sintering the one or more sinterable metallic parts in the furnace.

13. The method of claim 11 , further comprising extracting the one or more sinterable metallic parts from unbound regions of the metal powder, prior to sintering the one or more sinterable metallic parts in the furnace.

14. The method of claim 11 , wherein the radiation produced by the laser comprises visible light.

15. The method of claim 11 , wherein the metal powder further comprises one or more flow improvers.

16. The method of claim 11 , wherein the metal particles have a diameter between 1 μm and 100 μm.

17. The method of claim 16 , wherein the metal particles have a diameter between 5 μm and 25 μm.

18. The method of claim 11 , wherein the polymer comprises a polyolefin.

19. The method of claim 11 , wherein the metal particles are particles of stainless steel, carbon steel, copper, tool steel or titanium.

Assignees

• Desktop Metal Inc

Inventors

• Myerberg Jonah Samuel
• Hart Anastasios John

Classifications

• B22F1/102

  Metallic powder coated with organic material · CPC title

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title

• B29C64/255

  Enclosures for the building material, e.g. powder containers · CPC title

• B29K2023/12

  PP, i.e. polypropylene · CPC title

• B29K2023/06

  PE, i.e. polyethylene · CPC title