Constitutive analysis of wrought Mg-Gd magnesium alloys during hot compression at elevated temperatures

Abstract

Constitutive behaviors of the newly developed Mg-Gd alloys were studied to make it possible to reveal the effect of Gd addition on the high-temperature deformation behavior of magnesium. It was found that 0.5 wt% Gd is not adequate to increase the flow stress level. In contrast, in the case of 1.5 wt% Gd addition, the level of flow stress increased significantly due to the presence of enough solute Gd atoms. Based on the rigorous constitutive analysis, and by the aid of creep theories, the glide and climb of dislocations in the climb-controlled regime was found to be responsible for hot deformation of pure Mg; whereas the glide-controlled regime (viscous glide) for the Mg-1.5Gd alloy was identified as the controlling mechanism of deformation.