Enhanced Electroplasticity through Room-Temperature Dynamic Recrystallization in a Mg-3Al-1Sn-1Zn Alloy.

Abstract

It has been well known that electric pulse can be utilized to enhance the plasticity of metals, which is attributed to the change of dislocation dynamics, e.g., localized planar slip to homogeneous wavy slip. Here, we show another effect of pulse current, which facilitates texture weakening through room-temperature dynamic recrystallization and additionally improve the plasticity of a polycrystalline Mg-3Al-1Sn-1Zn alloy. By conducting a tensile test under electrical pulse, we found that the peak flow stress and fracture strain depend strongly on current density. As peak current densities increases, the flow stress drops and the fracture strain increases. Our Electron Backscatter Diffraction results suggest that dynamic recrystallization occurs at room temperature, which develops a weakened texture. Our work provides a new insight into electroplasticity mechanism in Mg alloys.