Methods of making parts from at least one elemental metal powder

Patent metadata

Field	Value
Publication number	US-2016107236-A1
Application number	US-201414176878-A
Country	US
Kind code	A1
Filing date	Feb 10, 2014
Priority date	Oct 22, 2013
Publication date	Apr 21, 2016
Grant date	—

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 about 60,000 pounds per square inch.

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

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

10 . The method of claim 9 , wherein the part density is from about 99 percent to 100 percent of a theoretical full density associated with the part, the sintered density is from about 80 percent to about 95 percent of the theoretical full density, and the cold-compacted density is from about 50 percent to about 85 percent of the theoretical full density.

11 . 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.

12 . 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.

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

14 . The method of claim 13 , wherein the portion is thermally cycled for a number of thermal cycles.

15 . The method of claim 14 , wherein the number of thermal cycles is from about 5 to about 25.

16 . The method of claim 14 , wherein each of the thermal cycles causes a crystallographic change of a material of the portion.

17 . The method of claim 1 , wherein the portion is thermally cycled in an inert atmosphere.

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

19 . The method of claim 1 , wherein the at least one elemental metal powder is at least one of a titanium powder, an aluminum powder, and a vanadium powder.

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

21 . The method of claim 20 , wherein the plurality of elemental metal powders include at least two of a titanium powder, an aluminum powder, and a vanadium powder.

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

23 . 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.

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

25 . The method of claim 24 , wherein the thermal-cycling pressure is about 2000 pounds per square inch.

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

27 . The method of claim 26 , 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

• B22F3/16 Primary

  in successive or repeated steps · CPC title

• B22F2003/248

  Thermal after-treatment · CPC title

• B22F3/24

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

• C21D1/785

  Thermocycling · CPC title