Abstract: A friction welding process providing a workpiece having a weld surface, and a second workpiece having a weld surface. The workpieces being welded together at respective weld surfaces. Oscillatory motion is affected to the workpieces such that one weld surface moves across the other, thereby raising the temperature at the weld surfaces to create a weld interface. The oscillatory motion is ceased and the weld surfaces cool to weld the workpieces together at the interface. The workpiece has an extending portion, and the weld surface is provided on the extending portion. The extending portion includes an apex region, which engages the second workpiece's weld surface. A side face extends from the apex region to provide a gap between the side face and the second workpiece's weld surface. The gap allows weld flash material to pass from the weld interface through said gap.

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).

Abstract: A disk for a BLISK rotary stage of a gas turbine engine includes a stub on the tapered circumferential surface of a turbine disk, the stub defining a weld joint surface on the radially outermost face of the stub. The weld joint surface follows the annulus curvature in axial and circumferential directions while remaining flat in a third direction. A blade is applied radially to the stub and linear friction welding of the blade to the stub is effected by oscillating the blade in said third direction while applying a welding force inwardly along the blade.

Abstract: A method of making a BLISK by linear friction welding, comprises providing a stub on the circumferential surface of a turbine disk and defining a weld joint surface on the radially outermost face of the stub. The weld joint surface follows the annulus curvature in axial and circumferential directions while remaining flat in a third direction. A blade is applied radially to the stub and linear friction welding of the blade to the stub is effected by oscillating the blade in said third direction while applying a welding force inwardly along the blade.

Abstract: A rotor disc which is suitable for carrying the fan blades of a ducted fan gas turbine engine is constituted by two sub-discs which are maintained in axially spaced apart relationship by a plurality of spacer members. The spacer members are generally axially extending and at least partially define the operational air flow path over the disc.