Rolls-royce Corporation

Arnold J Pratt

John O Fowler

John G Searle

James E Boardman

Anthony L Pratt

Bryan L Benn

A plurality of hollow blades are produced by assembling a plurality of titanium sheets and a plurality of titanium blocks into a stack. At least one of the sheets is provided with a stop off material on one of its surfaces at a plurality of longitudinally spaced pre-selected areas to prevent diffusion bonding at these areas to define the hollow interiors of the blades. The edges and ends of the sheets are welded together and the blocks are welded to the sheets. The assembly is heated and externally pressurised to diffusion bond the sheets and blocks together. The integral structure so formed is then heated and internally pressurised to superplastically form at least one of the sheets at each of the pre-selected areas to produce a plurality of hollow blades. Thereafter the hollow blades are separated from each other by machining and simultaneously producing the aerofoil shapes.

Method of manufacturing hollow articles by superplastic forming and

In a friction bonding operation the friction generating and weld forming forces are usually applied perpendicular to the joint faces. Thus, whenever the joint angle changes to component cassette part of the welding machine must be reset to a new angular orientation. This situation arises in the manufacture of a compressor BLUM (Bladed drUM) for a gas turbine engine, where the blades in successive stages are set at different HADE angles. The invention provides an improved component cassette in which the HADE angle is ignored. The cassette is interlocked with the workplace holder to provide a closed force loop to contain out-of-plane forces while retaining sufficient degrees of freedom to allow the friction generating and welding movements to proceed unimpeded.

Friction welding tooling

A feed arrangement for a rotating bar includes a rotary drive carrying a series of axially spaced clamping devices comprising collets through which the bar passes. The clamping devices are axially reciprocated in phased sequence and the collet of each device closes upon the bar while the device is moving forwards. The sequence is so controlled that at all times the bar is clamped by the collet of at least one forwardly moving device and is thereby continuously fed forwards while being rotated by the active clamping device.

Apparatus for continuous axial feeding of an elongate member

A method of making a titanium fan disc for a gas turbine engine comprises the steps of providing a pair of identical forged titanium cylinders each having a central bore and a flat end surface at right angles to its central axis, preparing the flat end surface of each cylinder to a high degree of smoothness, abutting the prepared surfaces of the cylinders one against the other in axial alignment, removing air from between said surfaces, and diffusion bonding the cylinders end-to-end by hot isostatic pressing to form the disc.

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Derbyshire, United Kingdom

Arnold J Pratt