Patent ID: 7052241

Claim:
A process for axially bonding the hub ( 109 ) of a titanium aluminide (TiAl) turbine rotor ( 103 ) to a pre-formed steel shaft ( 107 ) of a rotor shaft assembly ( 101 ) of a type used in a turbocharger for rotating about its axis ( 111 ) to drive a compressor, said process comprising: (a) axially mounting a preformed steel shaft ( 107 ), to the hub ( 209 ) of a compact ( 203 ) of said rotor ( 103 ), wherein said compact comprises a TiAl powder admixed with a binder, to form a mounted compact ( 201 ) optionally comprising a clearance ( 211 ) between said hub ( 209 ) of said compact ( 203 ) and said shaft ( 107 ), and (b) debinding and sintering said mounted compact ( 201 ), wherein said rotor compact ( 203 ) and said clearance ( 211 ) are selected to provide a tight fit of said hub ( 209 ) to said shaft ( 107 ) during sintering, whereby said rotor ( 103 ) and said shaft ( 107 ) are bonded by metallurgical bonding to form said rotor shaft assembly ( 101 ).