Research status of superplastic deformation mechanism of coarse-grained aluminum alloys

Basic characteristics of superplasticity of coarse-grained aluminum alloys at home and abroad were described. The superplastic deformation mechanism of coarse-grained aluminum alloy was classified and summarized, which mainly included diffusional creep mechanism, grain boundary slip mechanism with diffusion creep, dislocation slip/creep mechanism, liquid phase regulation mechanism, dynamic recrystallization mechanism, cooperative grain boundary sliding mechanism and cavities growth mechanism. In view of urgency of developing superplasticity of aluminum alloy at low cost, application of coarse-grained materials was forecasted. It was pointed out that in addition to large grains, superplasticity under high strain rate and low temperature condition was also the current research direction of aluminum alloy deformation.