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 vessel is provided having a first chamber 1 open to atmospheric pressure for receiving liquid metal and a second chamber 2 from which the metal is dispensed interconnected with the first chamber. The second chamber is sealed and coupled to means 4, 6 for reducing the pressure therein to sub-atmospheric whereby to create a higher level of metal in said second than said first chamber.The first and second chambers may be interconnected via a refractory filter.