Microstructural Evolution of AZ31 under the Application of High Density Electric Current Pulses

The microstructural evolution in annealed Mg-3Al-1Zn (AZ31) magnesium alloy during high density electric current pulses (ECP) treatment is investigated by using a same current density with different processing numbers. It is found when the processing number of the ECP treatment is not greater than four times, the grains are refined and more homogenized, and the texture intensity obtained from the (0002) pole figure appears an obvious enhancement from 11.22 to 22.88. However, increasing the repeated ECP processing number will cause the coarsening of grain size and the decreasing of the texture intensity. The mechanism of the microstructural evolution during ECP treatment is discussed from the point of view of grain boundary motion.