TENSILE CREEP DEFORMATION AND FRACTURE, BEHAVIORS OF THE LAMELLAR TiAl ALLOY OF ELEMENTAL POWDER METALLURGY

摘要

Gamma TiAl alloy is known to be one of the strongest candidate materials for the light and high temperature structural materials in advanced gas turbine jet engine and the engine valves in automobile because of their high specific strength at elevated temperature (1). It is known that the mechanical properties of the gamma TiAI alloys are strongly dependent on their microstructure (2). Duplex structure has been developed to have available room temperature ductility, but this microstructure shows poor creep resistance and low fracture toughness compared with lamellar structure (3,4). Therefore, many researchers have concentrated to develop the lamellar structured gamma TiAI alloy and to evaluate their mechanical properties (5).