EFFECTS OF MICROSTRUCTURE ON THE MECHANICAL-PROPERTIES AND FRACTURE OF GAMMA-BASE TITANIUM ALUMINIDES

[摘要] The effect of microstructure on mechanical properties and fracture of gamma-base titanium aluminides was investigated. As-cast binary titanium aluminides containing different levels of aluminium ranging from 44 to 51 at.% were prepared for tensile tests, fracture toughness tests and creep rupture tests. The test results indicated that the bulk strength determined by hardness measurements increases with decreasing aluminium content. However, the highest tensile strength, fracture toughness and creep resistance were obtained in the Ti-48.2at.%Al alloy which consisted of alpha-2-gamma lamellae with serrated grain boundaries. The factors and mechanisms responsible for the fracture process of gamma-base titanium aluminides are discussed in relation to microstructure.

[发布日期] 1991-09-15