To enhance the heating efficiency and the formability of AZ31 magnesium alloy, the assistance heating method is adopted during the hot bulging process. The free bulging test of coarse grained and fine grained AZ31 magnesium alloy sheet was carried out. During the forming process, the effects of pulse current on the formed sheet combine both thermoelectricity and electro-plasticity. Directional and asymmetrical deformation of the coarse-grained AZ31 magnesium alloy sheet by the effect of pulse current is observed and analyzed. But in the same processing condition, the deformation of fine grained AZ31 magnesium alloy sheet is symmetrical. To investigate the influence of electron wind force on pulse current auxiliary bulging process, the simulation of AZ31 magnesium alloy pulse current auxiliary bulging based on the electron wind force value calculated by mathematical model was performed using the Marc software. The bulging simulation result showed a special phenomenon that the shape of the bulging specimen is unsymmetrical and the dome deviated from the symmetry axis to the side of positive pole. The simulation results were basically consistent with the experimental results. The deformation properties, microstructure characteristics, dislocation movement of the AZ31 magnesium alloy during gas bulging processing by the pulse current are investigated.
Crystal-plasticity finite-element analysis of inelastic behavior during unloading in a magnesium alloy sheet
