Abstract: A friction welding process comprises providing a first workpiece (10) having a first weld surface (16), and a second workpiece (12) having a second weld surface (18). The first and second workpieces (10, 12) can be welded together at the first and second weld surfaces (16, 18). The workpieces (10, 12) are arranged in engagement with each other at the weld surfaces (16, 18). Relative oscillatory motion is affected to the workpieces (10, 12) such that at least one weld surface moves across the other, thereby raising the temperature at the weld surfaces (16, 18) to create a weld interface. The relative oscillatory motion is ceased and the weld surfaces (16, 18) are allowed to cool to weld the first and second workpieces (10, 12) together at the interface. The first workpiece (10) has an outwardly extending portion (15), and the first weld surface (16) is provided on the outwardly extending portion (15). The outwardly extending portion (15) includes an apex region (14), which engages the second weld surface (18).

Abstract: A method of making an aerofoil blisk (10) comprising a plurality of aerofoil blades (12) joined to a disc (14) to extend radially outwardly therefrom includes the step of forming a blade member (28) having a stub (30) for joining to the disc (14), the stub (30) having a taper ratio of less than 2. The stub (30) of the blade member (28) may be joined to the disc (14) by linear friction welding, and excess material may subsequently be machined from the blade member (28) to form the blade (12).