Hot deformation behavior and processing map of Mg-2Zn-1Al-0.2RE alloy

In this study, uniaxial hot compression tests were carried out between 200 and 400 degrees C over strain rates of 0.001-1 s(-1) to investigate the hot deformation behavior of Mg-22n-1Al-0.2RE alloy with coarse grains. The average activation energy was measured to be 174.51 kJ/mol. In addition, a constitutive relation based on the Arrhenius equation was established. Dynamic recrystallization (DRX) kinetics were studied by Avrami equation to characterize the evolution of DRX volume fraction. DRX was favored at high temperatures of 300-400 degrees C and low strain rates of 0.001-0.01 s(-1). According to dynamic material model and Prasad's instability criterion, a maximum power dissipation of 38% and 32% occurs at 400 degrees C/0.001 s(-1) and 400 degrees C/0.01 s(-1), respectively. According to the processing map, 330-400 degrees C/0.001-0.01 s(-1) was determined as the optimum deformation parameter range. (C) 2020 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.