Hot deformation behaviors of WE71 alloy under plain strain compression at elevated temperature

Hot deformation behaviors of WE71 (Mg-7Y-1Nd-0.5Zr) alloy was investigated by plain strain compression tests conducted at temperatures ranging from 350 degrees C to 500 degrees C and strain rates varying from 0.01 s(-1) to 10 s(-1). Results show that the hot deformation of WE71 was accompanied by the precipitation of rich Zr phase with granular shape and block-shaped phase rich in element Y. When deformed at low temperature and high strain rate, the softening behavior of the alloy was synergically determined by shear bands propagation, adiabatic heating, twinning formation and dynamic recrystallization (DRX). For the conditions of high temperature and high strain rate, DRX was the major softening mechanism while the formation and annihilation of extension twinning resulted in a special flow curve characteristic at the strain of around 0.3. According to the microstructural observations, it can be concluded that the irregular flow curves of WE71 alloy during plain strain compression process are mainly ascribed to shear bands propagation, adiabatic heating, twinning formation and DRX.