US 7,594,325 B2
	Aerofoil and a method of manufacturing an aerofoil
Simon Read, Derby (United Kingdom)
Assigned to Rolls-Royce plc, London (United Kingdom)
Filed on Aug. 25, 2005, as Appl. No. 11/210,872.
Claims priority of application No. 0421033.2 (GB), filed on Sep. 22, 2004.
Prior Publication US 2007/0243069 A1, Oct. 18, 2007
Int. Cl. B21D 53/78 (2006.01); B63H 1/26 (2006.01); B22F 3/00 (2006.01)

U.S. Cl. 29—889.71  [29/889; 29/889.72; 416/229 R; 416/232; 428/547; 428/548; 428/550]

5 Claims

1. A method of manufacturing an aerofoil comprising the steps of: a) forming at least two metal workpieces, b) applying a stop off material to one surface of one of the at least two metal workpieces, c) arranging the at least two metal workpieces in a stack with the stop off material between the two metal workpieces, d) sealing the edges of the at least two metal workpieces together to form a sealed assembly, e) evacuating an interior of the sealed assembly, f) heating and applying pressure to diffusion bond the at least two metal workpieces together except where the stop off has been applied to form an integral structure, g) heating and pressurising an interior of the integral structure to form a cavity in the integral structure, h) placing the integral structure in a die, i) filling the cavity in the integral structure with metal powder and a foaming agent and j) applying heat to produce a metal foam in the cavity in the integral structure and to form the at least two metal workpieces into an aerofoil shape with appropriate twist and camber in the die.