Research of initial dynamic recrystallisation for AZ31 alloy with pulse current

Tensile tests with pulse current for AZ31 alloy under room temperature and different voltages were carried out. Pulse current influence on the critical condition of initial dynamic recrystallisation for AZ31 alloy was investigated. The critical value was determined by one-parameter approach and validated by metallographic observation. The results showed that, with current voltage increased, the ultimate strength decreased, and the amount of strain hardening before reaching the ultimate strength decreased. When the voltage increases, high dynamic recrystallisation degree can be obtained, but due to the high electroplastic effect, the dynamic recrystallisation grain grows up and the material mechanical property deteriorates. The microstructure observation proved that the critical condition for initial dynamic recrystallisation can be determined with the one-parameter approach.