Analysis of grain growth during superplastic deformation

The microstructural mechanism of grain growth during superplastic deformation is studied in this paper. A new model that considers grain growth is proposed and applied to conventional superplastic materials (Zn-Al alloy, LY12CZ alloy, and 7475 Al alloy). The relationships between the strain, strain rate, test temperature, initial grain size and grain growth in superplastic materials are discussed. The theoretical predictions for superplastic deformation that are presented show good agreement with the experimental data. The effect of the variation of strain rate sensitivity (m value) on the strain limit of superplastic deformation is investigated, and the theoretically calculated values are compared with the experimental results.