Finite element analysis of superplastic blow forming of fine-grained magnesium alloy sheet

The process of superplastic blow forming was simulated and analyzed by the finite element software. The effect of the strain rate sensitivity index and forming pressure on the wall thickness distribution of forming parts were studied. Meanwhile the changes of strain rate during the forming process were simulated. It is shown that strain rate sensitivity index and forming pressure have a great impact on the thickness uniformity. When strain rate sensitivity index of 0.5 and forming pressure of 0.8 MPa, the thickness uniformity of forming parts is good and the highest thinning rate is 39%. The thickness gradients appear during blow forming due to the differences in the local stresses.