EFFECTS OF TWO－STEP HEAT－TREATMENT ON MICROSTRUCTURE AND PROPERTIES OF TiAl INTERMETALLICS
(Powder metallurgy Research Institute; Central South University of Technology; Changsha 410083)
Abstract: Special heat-treatment was used to improve the mechanical properties at room temperature of TiAl-based alloys which were isothermal forged (1050℃, 82%). The results showed that proper two-step heat treatment could decrease or eliminate large-grained lamellar structure produced by inhomogeneous deformation,and gain fine, homogeneous duplex microstructure. And the volume ratio of γ:α2/γ was about 1:1. The room temperature ductility of the TiAl alloys reached 3. 3% with high strengths.
Key words: intermetallics heat treatment tensile properties