MECHANISM OF SUPERPLASTIC DEFORMATION IN ALUMINIUM ALLOY 2214

During the superplastic deformation of warm-rolled aluminium alloy 2214,the dislocation density in the grain remains equilibration to some extent because of the effect of dynamic recovery and recrystallization. The dominant deformation mechanism is grain-boundary sliding.The dislocation sliding in grain and diffusion creep, as two kinds of important coordination mechanism,promote the development of grain-boundary sliding.The superplastic deformation mechanism accords with the model of dislocation coordinating grain-boundary sliding.