Composite connection method for titanium-aluminum alloy turbine and steel shaft

The invention discloses a composite connection method for a titanium-aluminum alloy turbine and a steel shaft. The composite connection method mainly comprises the steps that 1, friction welding is carried out on a machined structural steel shaft and a nickel-based high-temperature alloy transition body, and then annealing treatment is carried out; 2, the end matching surface of a titanium-aluminum alloy turbine shaft and the nickel-based high-temperature alloy transition body is designed to be in a corrugated shape, a brazing filler metal is placed at the end of the titanium-aluminum alloy turbine shaft, the nickel-based high-temperature alloy transition body is heated in an induction heating mode, and the heated nickel-based high-temperature alloy transition body is pressed downwards into the titanium-aluminum alloy turbine shaft assembled with the brazing filler metal; and 3, a titanium-aluminum turbine rotating shaft subjected to interference assembly is subjected to brazing treatment in a vacuum brazing