Effect of Er addition on recrystallization, texture, and mechanical properties in a binary Mg-Er alloy

Abstract

In this work, the role of Er addition on texture, recrystallization and mechanical properties has been systematically studied in a binary Mg-Er alloy. As-cast Mg-1Er and Mg-5Er (wt. %) alloys were hot-rolled and annealed at 400 °C for different durations from 3 min to 60 min. The evolution of microstructure and texture were studied using electron back-scattered diffraction (EBSD), high resolution transmission electron microscopy (HRTEM) and X-Ray diffraction. Recrystallization kinetics were analyzed using combined hardness measurements and Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. Additionally, tensile testing was conducted on hot-rolled and recrystallized samples. Er addition significantly influenced the propensity of twinning. It was observed that the addition of Er increased the proportion of contraction twins (CT) and double twins (DT) but lowered the extension twin (ET). Similarly, both as-rolled and recrystallized textures were influenced by Er addition. Increasing Er content reduced basal texture intensity. Quantitative assessment of recrystallization fraction suggested that Er addition lowers the recrystallization kinetics in Mg-Er alloys. The mechanical properties were superior in Mg-5Er alloys in both hot-rolled and annealed samples. Among several factors, the influence of Er addition on deformation mechanisms, solid solution strengthening, and solute drag effect seems to play a dominant role in explaining the results.