Abstract:A γ-TiAl base alloy with the composition of Ti-34Al-2Mn(wt--%)was prepared by consum- able electrode arc-melting technique.The effect of homogenization processing following arc-melt- ing on its microstructure and mechanical properties was investigated.The emphases were placed on the microstructural evolution during solidification and homogenization,and the relationship be- tween microstructure and ductility.It has been determined that the samples annealed at 900℃ for 20 h exhibit the best ductility compared with those treated at other temperatures up to 1 100℃,and they have a mixed structure of equiaxed grain of γ-TiAl single phase and some prima- ry lamellar grains which include three types of interfaces,i.e.,α₂/γ,/γ/γ_S,γ/γ_T,maintaining specific orientaion relationships between both sides.The ductility improvement is believed to be as- sociated with existence of suitable amount of α₂-Ti₃Al phase and the refinement of grains ob- tained at 900℃.

Key words: Ti-34Al-2Mn Alloy; homogenization; microstructure; properties