Method for creating porous structures by particle expansion

Patent metadata

Field	Value
Publication number	US-10280485-B2
Application number	US-201514811049-A
Country	US
Kind code	B2
Filing date	Jul 28, 2015
Priority date	Jul 28, 2014
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

A process for producing a metal foam. The process includes mechanically working a metallic powder such that oxide particles are finely dispersed within a metallic matrix of the metallic particles that make up the metallic powder. The mechanically worked metallic powder is then annealed in a reducing atmosphere, which in turn reduces the oxide particles within the metallic particles such that H2O gas molecules (steam) are formed within the metallic matrix and intraparticle porosity is produced.

First claim

We claim:

1. A process for producing a metal foam comprising:
mechanically working a metallic powder such that oxide particles are finely dispersed within a metallic matrix; and
annealing the mechanically worked metallic powder in a reducing atmosphere, the annealed metallic powder having intraparticle porosity formed by chemical conversion of the oxide particles into steam.

2. The process of claim 1 , wherein the metallic powder is a copper containing metallic powder.

3. The process of claim 2 , wherein the mechanical working is ball milling the metallic powder.

4. The process of claim 3 , wherein the ball milling alloys copper particles with non-copper particles.

5. The process of claim 4 , wherein the non-copper particles are antimony particles.

6. The process of claim 3 , wherein the ball milling is cryogenic ball milling.

7. The process of claim 3 , wherein the ball milling is room temperature ball milling.

8. The process of claim 1 , wherein the reducing atmosphere is an argon-hydrogen atmosphere.

9. The process of claim 1 , wherein the annealing occurs at a temperature less than or equal to 800° C.

10. The process of claim 9 , wherein the annealing occurs at a temperature less than or equal to 700° C.

11. The process of claim 10 , wherein the annealing occurs at a temperature less than or equal to 600° C.

12. The process of claim 1 , further comprising compacting the annealed ball milled metallic powder into a desired shape, the desired shape having a porosity of at least 40%.

13. The process of claim 12 , wherein the porosity is at least 50%.

14. The process of claim 13 , wherein the porosity is at least 60%.

15. The process of claim 14 , wherein the porosity is at least 65%.

16. A process for a metal foam component comprising:
providing a plurality of metallic particles, each of the plurality of metallic particles having a metallic matrix;
ball milling the plurality of metallic particles such that oxide particles are finely dispersed within the metallic matrix of at least a portion of the metallic particles;
annealing the mechanically worked metallic powder in a reducing atmosphere containing hydrogen, the oxide particles reacting with the hydrogen to form steam and form intraparticle porosity within the metallic matrix of the at least a portion of the metallic particles; and
sintering the annealed mechanically worked metallic powder into a desired shape, the desired shape having a metal foam structure with a porosity of at least 40%.

17. The process of claim 16 , wherein the ball milling is cryogenic ball milling.

18. The process of claim 16 , wherein the ball milling is room temperature ball milling.

19. The process of claim 16 , wherein the annealing occurs at a temperature less than or equal to 700° C.

20. The process of claim 16 , wherein the porosity is at least 60%.

Assignees

• Millersville Univ Of Pennsylvania
• Us Army

Inventors

• Atwater Mark Andrew
• Darling Kris Allen
• Tschopp Jr Mark Allen

Classifications

• B22F2009/043

  by ball milling · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• C22C1/08 Primary

  Alloys with open or closed pores · CPC title

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• B22F3/1143

  involving an oxidation, reduction or reaction step · CPC title