Methods of making parts from at least one elemental metal powder

Patent metadata

Field	Value
Publication number	US-10189087-B2
Application number	US-201414176878-A
Country	US
Kind code	B2
Filing date	Feb 10, 2014
Priority date	Oct 22, 2013
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

One aspect of the disclosure relates to a method of making a part from at least one elemental metal powder. The part has a near-net shape, a part volume, and a part density. The method includes providing a sintered preform having a sintered density and separating a portion from the sintered preform. The portion has a portion volume exceeding the part volume and a portion shape different from the near-net shape of the part. The method also includes thermally cycling the portion for a thermal-cycling time period at a thermal-cycling pressure while superplastically deforming the portion to form the part having the near net shape and the part density.

First claim

What is claimed is:

1. A method of making a part from at least one elemental metal powder, the part having a near-net shape, a part volume, and a part density, the method comprising:
providing a sintered preform having a sintered density;
separating a portion from the sintered preform, the portion having a portion volume exceeding the part volume and a portion shape different from the near-net shape of the part; and
thermally cycling the portion for a thermal-cycling time period at a thermal-cycling pressure while superplastically deforming the portion to form the part having the near net shape and the part density.

2. The method of claim 1 , wherein the sintered preform is formed by sintering a cold-compacted preform for a sintering time period at a constant temperature.

3. The method of claim 2 , wherein the constant temperature is from about 1900 degrees Fahrenheit to about 2500 degrees Fahrenheit.

4. The method of claim 2 , wherein the sintering time period is from about 2 hours to about 20 hours.

5. The method of claim 2 , wherein the cold-compacted preform has a cold-compacted density and is formed by cold-compacting the at least one elemental metal powder for a cold-compacting time period at a cold-compacting temperature and a cold-compacting pressure.

6. The method of claim 5 , wherein the cold-compacted density is from about 50 percent to about 85 percent of a theoretical full density associated with the part.

7. The method of claim 5 , wherein the cold-compacting pressure is higher than the thermal-cycling pressure.

8. The method of claim 7 , wherein the part density is greater than the sintered density and the sintered density is greater than the cold-compacted density.

9. The method of claim 5 , wherein forming the cold-compacted preform further includes attriting the at least one elemental metal powder before cold-compacting the at least one elemental metal powder.

10. The method of claim 1 , further comprising processing the part after deforming the portion to the near-net shape to change the near-net shape to a net shape.

11. The method of claim 1 , wherein the portion is thermally cycled between a first temperature and a second temperature.

12. The method of claim 11 , wherein the portion is thermally cycled for a number of thermal cycles.

13. The method of claim 12 , wherein each of the thermal cycles causes a crystallographic change of a material of the portion.

14. The method of claim 1 , wherein the thermal-cycling time period is less than about an hour.

15. The method of claim 1 , wherein the part is made from a plurality of elemental metal powders.

16. The method of claim 1 , wherein the sintered density is from about 80 percent to about 99 percent of full density.

17. The method of claim 1 , wherein the sintered density is from about 95 percent to about 99 percent of a theoretical full density associated with the part.

18. The method of claim 1 , wherein the thermal-cycling pressure is constant.

19. The method of claim 1 , wherein the sintered preform has a cylindrical shape.

20. The method of claim 19 , wherein the sintered preform has a diameter and a first height, and wherein the portion of the sintered preform has the diameter of the sintered preform and has a second height less than the first height.

Assignees

• Boeing Co

Inventors

• Matsen Marc R
• Carter Matthew Douglas
• Wilkinson Carey Eugene
• Firth Lee C

Classifications

• B22F3/156 Primary

  by a pressure medium in liquid or powder form · CPC title

• B22F2003/248

  Thermal after-treatment · CPC title

• C21D1/785

  Thermocycling · CPC title

• B22F3/24

  After-treatment of workpieces or articles {(B22F3/1146 takes precedence)} · CPC title

• B22F3/16 Primary

  in successive or repeated steps · CPC title