# US 7,407,622 B2 · Method of manufacturing a metal article by powder metallurgy

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,407,622 B2
- Document ID: US7407622B2
- Status: Granted
- Kind: B2
- Application number: 11/273,027
- Filed: 2005-11-15
- Published: 2006-06-15
- Granted: 2008-08-05
- Earliest claimed: 2004-12-10
- Assignees: ROLLS-ROYCE plc
- Inventors: Wayne E Voice; Junfa Mei
- Web page: https://patentgrep.com/patent/US7407622B2

## CPC

- B22F 5/04: of turbine blades
- B22F 5/10: of articles with cavities or holes, not otherwise provided for in the preceding subgroups
- B22F 2998/10: Processes characterised by the sequence of their steps
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER

## Abstract

A method of manufacturing a fan blade (26) for a gas turbine engine by powder metallurgy comprises the steps of forming a container (52) and placing at least one metal insert (52) at a predetermined position within the container (52) and filling the container (52) with metal powder (60). The at least one metal insert (62) has a predetermined pattern of stop off material (68,70) on at least one surface of the metal insert (64,66). The container (52) is evacuated and then sealed. The container (52) is hot pressed to consolidate the metal powder (60) into a consolidated metal powder preform (72). The container (52) is removed from the consolidated metal powder preform (72). The consolidated metal powder preform (72) is heated and a fluid is supplied to the predetermined pattern of stop off material (68,70) to hot form at least a portion of the consolidated metal powder preform (72) to form the hollow metal fan blade (26).

## Claims

### Claim 1

A method of manufacturing a hollow article by powder metallurgy comprising the steps of (a) forming a container, (b) placing at least one metal insert at a predetermined position within the container and filling the container with metal powder, the at least one metal insert having a predetermined pattern of stop off material on at least one surface of the metal insert, (c) evacuating the container, (d) sealing the container, (e) hot pressing the container to consolidate the metal powder into a consolidated metal powder preform, (f) removing the container from the consolidated metal powder preform, (g) heating the consolidated metal powder preform and supplying a fluid to the predetermined pattern of stop off material to hot form at least a portion of the consolidated metal powder preform to form a hollow metal article.

### Claim 2 (depends on 1)

A method as claimed in claim 1 wherein step (a) comprises forming two workpieces and welding the workpieces together to form the container.

### Claim 3 (depends on 2)

A method as claimed in claim 2 wherein step (a) comprises cold pressing the workpieces to a predetermined shape to form the container.

### Claim 4 (depends on 1)

A method as claimed in claim 1 wherein step (a) comprises forming the container from metal.

### Claim 5 (depends on 1)

A method as claimed in claim 1 wherein step (e) comprises hot pressing the container in shaped dies.

### Claim 6 (depends on 1)

A method as claimed in claim 1 wherein step (e) comprises hot isostatic pressing.

### Claim 7 (depends on 1)

A method as claimed in claim 1 wherein step (f) is selected from the group comprising peeling off the container and dissolving the container in an acid.

### Claim 8 (depends on 1)

A method as claimed in claim 1 wherein the metal powder is titanium alloy.

### Claim 9 (depends on 1)

A method as claimed in claim 1 wherein the metal insert comprises a titanium alloy.

### Claim 10 (depends on 1)

A method as claimed in claim 1 wherein the stop off material comprises yttria.

### Claim 11 (depends on 1)

A method as claimed in claim 1 wherein step (g) comprises supplying a gas to the predetermined pattern of stop off material.

### Claim 12

A method as claimed in 1 wherein the hollow article is a component of a gas turbine engine.

### Claim 13 (depends on 12)

A method as claimed in claim 12 wherein the hollow article is selected from the group consisting of a compressor blade, a compressor vane, a fan blade and a fan outlet guide vane.