Abstract: A frictional welding process for joining a titanium aluminide turbine to a titanium alloy shaft is disclosed. The disclosed process includes preheating the turbine to a designated temperature, providing a specially-designed joining interface geometry at the distal end of the shaft and optimizing the frictional welding parameters. The frictional welding is carried out in multiple steps but, while the shaft is being spun by a rotating chuck, two different pressures and two different time periods are used until the narrower portions of the distal end of the shaft have been fused onto the welding surface of the turbine. Then, an additional forging step with yet another engagement pressure between the shaft and the turbine is carried out without rotation of the shaft.

Abstract: A frictional welding process for joining a titanium aluminide turbine to a titanium alloy shaft is disclosed. The disclosed process includes preheating the turbine to a designated temperature, providing a specially-designed joining interface geometry at the distal end of the shaft and optimizing the frictional welding parameters. The frictional welding is carried out in multiple steps but, while the shaft is being spun by a rotating chuck, two different pressures and two different time periods are used until the narrower portions of the distal end of the shaft have been fused onto the welding surface of the turbine. Then, an additional forging step with yet another engagement pressure between the shaft and the turbine is carried out without rotation of the shaft.

Abstract: A method of bonding two materials by friction welding method. A first material may be made from a titanium aluminide intermetallic alloy and a second material may be made from a titanium alloy. The first material may be heated to a temperature between about 300° C. and about 800° C. The second material may be rotated relative to the first material. The first material and the second material may be pressed against each other while one of the first material, and the second material is rotated. The rotation of one of the first material and the second material may be stopped, and the first material and the second material may be pressed against each other after the rotation of one of the first material and the second material is stopped.