Effect of Strain Rate on Dynamic Recrystallization in a Magnesium Alloy under Compression at High Temperature

Abstract

Interrupted uniaxial compression tests were performed on an extruded Mg-Al-Mn magnesium alloy (AM30) at 450°C and various strain rates of 0.001 s−1, 0.1 s−1, 0.5 s−1 and 0.8 s−1. Texture and microstructure evolution were examined using electron back scattered diffraction (EBSD) and X-ray diffraction (XRD) techniques. Twinning was found to be ubiquitous at high temperature but provided that a highly enough strain rate was applied. The results show that the deformation microstructure evolves with strong dependence on the strain rate as twinning triggers and non-basal slips become harder. Schmid’s factor and slip traces analyses elucidated the driving forces controlling dynamic recrystallization mechanisms and emphasized on the role played by extension twinning and non-basal slips.