Abstract:Dynamic recrystallization has great effect on the superplastic deformation and hot working of TiAl based alloys. Through TEM analyses, the dynamic recrystallization in Ti_-33Al_-3Cr_-0.5Mo alloy after superplastic deformation was studied. The results show that, dynamic recrystallization which occurs not only in grain boundaries but also inside grains can remarkably refine grains. It is deduced that,dynamic recrystallization can be resulted from grain boundary sliding, and which can be enhanced by dynamic recrystallization.

Key words: TiAl based alloy　dynamic recrystallization　superplastic deformation