A comparative study of deformation behaviors and ductility improvement in Mg–Gd–Zr and Mg–Zr cast alloys

Abstract

This study investigates the impact of Gd elements on the enhancement of ductility in the Mg–Gd–Zr alloy. The deformation behavior at room temperature of the cast Mg–Gd–Zr alloy and the cast Mg–Zr alloy was examined using the EBSD-assisted slip trace method. The quantitative analysis of the initiation ratio of each slip system in the two alloys revealed that the Mg–Gd–Zr alloy had a higher ratio of non-basal slip systems. The experimental determination of the critical resolved shear stress (CRSS) ratios of non-basal slip to basal slip for both alloys indicated that the Gd elements could reduce this ratio, facilitating the initiation of more non-basal slip systems to accommodate strain. Furthermore, the segregation of Gd elements at grain boundaries was observed to enhance the grain boundary strength of the alloy, which is a significant factor in the enhancement of ductility.

Keywords

• Magnesium alloys
• Ductility
• Non-basal slip
• Grain boundary cohesion