TiAl turbine rotor and method of manufacturing

摘要

A turbine rotor consisting of a wheel made of a TiAl alloy of good heat resistance and a rotor shaft made of a steel with good bonding strength is disclosed. As the shaft material a structural steel or a martensitic heat resistant steel is used. A TiAl turbine wheel made by precision casting is butted to the shaft with insertion of a brazing filler in the butted interfaces and stress of 0.01 kgf/mm2 or higher but lower than yield stress of the shaft is applied on the butted interfaces under heating by high frequency induction heating in atmosphere of an inert gas or a reducing gas to a temperature higher than the liquidus temperature of the brazing metal but not exceeding 100 DEG C. above the liquidus temperature. Turbine rotors with good accordance of the axes of the wheel and the shaft will be obtained by fitting a projection (or recess) and a recess (or projection) formed at the base of the wheel and the end of the shaft concentrically to the outer shape thereof, and by brazing the ring-shaped area outside the fitted parts.