Electroplastic effect in AZ31B magnesium alloy sheet through uniaxial tensile tests
(1. Institute of Forming Technology & Equipment, Shanghai Jiao Tong University, Shanghai 200030, China;
2. General Motor Chinese Science Laboratory Institute, Shanghai 201206, China)
2. General Motor Chinese Science Laboratory Institute, Shanghai 201206, China)
Abstract: The electroplastic effect in AZ31B magnesium alloy sheet was investigated through uniaxial tensile tests. In order to show the athermal effect of the electrical pulses, two types of uniaxial tensile tests at the same testing temperature were carried out: uniaxial tension in environmental cabinet and uniaxial tension with electrical pulses. In addition, the distribution of temperature field in the cross-section area during uniaxial tension with electrical pulses was simulated. The results show that the distribution of temperature field along the cross-section area is homogeneous. By comparing the true stress-true strain curves of AZ31B alloy under uniaxial tensile tests, the athermal effect with electrical pulses was confirmed. The microstructure evolution after the uniaxial tension was studied by optical microscopy. The results indicate that the electrical pulses induced dynamic recrystallization plays an important role in the decrease of flow stress. Finally, a flow stress model of AZ31B sheet taking the influence of electroplastic effect into account was proposed and validated. The results demonstrate that the calculated data fit the experimental data well.
Key words: AZ31B magnesium alloy sheet; electroplastic effect; temperature field simulation; microstructure evolution