Numerical research on the process of superplastic sheet metal forming

摘要

In this paper, the microstructure mechanism of the grain growth during superplastic forming is analyzed. Using the new constitutive equation for superplastic forming, the influences of the strain, the strain rate, test temperature and the initial grain size on the grain growth in superplastic metals are studies. The new constitutive equation integrating the microstructure mechanism and the macro-phenomenon of superplasticity is introduced into the rigid-plastic finite element simulation program to study the superplastic forming. The effects of the geometric shape parameters of the die on the superplastic constrained bulging process are investigated, and the ununiformity in the thickness distribution of specimen is analyzed.