Powder hot isostatic pressing cycle

Patent metadata

Field	Value
Publication number	US-2023339021-A1
Application number	US-202118028034-A
Country	US
Kind code	A1
Filing date	Sep 21, 2021
Priority date	Sep 24, 2020
Publication date	Oct 26, 2023
Grant date	—

Abstract

A method of fabricating, at least in part, an article from a precursor thereof, the method comprising: providing the precursor, wherein the precursor comprises a metal having a closed pore therein; and hot isostatic pressing, HIPing, the precursor at an Nth temperature of a set of temperatures, at an Nth pressure of a set of pressures and for an Nth duration of a set of durations, thereby fabricating, at least in part, the article; wherein HIPing the precursor comprises regulating the set of temperatures, the set of pressures and/or the set of durations to control, at least in part, a morphology of the closed pore.

First claim

1 . A method of fabricating an article from a precursor thereof, the method comprising:
providing the precursor, comprising encapsulating a powder of an α + β Ti alloy in a container, wherein the powder is formed by electrode induction gas atomisation; EIGA; cold pressurisation of the precursor by isostatically compressing the precursor at a first pressure, thereby providing a compressed precursor; and hot isostatic pressing the compressed precursor at an Nth pressure in a range from 75 MPa to 150 MPa and at an Nth temperature in a range from 850° C. to 950° C., thereby fabricating the article; wherein a ratio of the first pressure to the Nth pressure is in a range from 1 : 2 to 9 : 10.

2 . The method according to claim 1 , wherein a ratio of the first pressure to the Nth pressure is in a range from 2 : 3 to 17 : 20.

3 . The method according to claim 1 , wherein cold pressurisation of the precursor by isostatically compressing the precursor at the first pressure is without applying heating or cooling.

4 . The method according to claim 1 , wherein particles of the powder comprise entrapped bubbles of argon.

5 . The method according to claim 4 , wherein the particles of the powder have a dimension of at least 50 µm.

6 . The method according to claim 1 , comprising depressurising the article isothermally from the Nth pressure towards ambient pressure, and subsequently, cooling the depressurised article from the Nth temperature towards ambient temperature.

7 . The method according to claim 6 , wherein depressurising the article isothermally from the Nth pressure towards ambient pressure comprises depressurising the article isothermally from the Nth pressure to ambient pressure.

8 . The method according to claim 6 , wherein cooling the depressurised article from the Nth temperature towards ambient temperature comprises cooling at a first cooling rate and subsequently, cooling at a second cooling rate, wherein the first cooling rate is slower than the second cooling rate.

9 . The method according to claim 6 , wherein cooling the precursor comprises isobarically cooling the precursor.

10 . The method according to claim 9 , wherein isobarically cooling the precursor is at ambient pressure.

11 . The method according to claim 6 , wherein cooling the depressurised article from the Nth temperature towards ambient temperature comprises isobarically cooling the precursor from the Nth temperature to an N+1th temperature, wherein the N+1th temperature is at least 80% of the Nth temperature.

12 . The method according to claim 1 , wherein cold pressurisation of the precursor is at ambient temperature.

13 . The method according to claim 1 , wherein the α + β Ti alloy is a Ti-6Al-4V alloy.

14 . The method according to claim 1 , wherein the Nth pressure is in a range from 90 MPa to 125 MPa and/or the Nth temperature is in a range from 875° C. to 925° C.

15 . The method according to claim 1 , wherein the article is an aerospace component, a vehicle component, or a medical component.

Assignees

• Bae Systems Plc

Inventors

• Price Howard James
• Stewart Peter Neil
• Gallagher Sean

Classifications

• B22F3/16 Primary

  in successive or repeated steps · CPC title

• B22F3/04

  by applying fluid pressure {, e.g. by cold isostatic pressing [CIP]} · CPC title

• B22F3/15 Primary

  Hot isostatic pressing · CPC title

• B22F2301/205

  Titanium, zirconium or hafnium · CPC title

• B22F2304/10

  Micron size particles, i.e. above 1 micrometer up to 500 micrometer · CPC title