Influence of Nd or Ca addition on the dislocation activity and texture changes of Mg–Zn alloy sheets under uniaxial tensile loading

Abstract

In situ hard X-ray diffraction experiments were carried out to investigate the dislocation slip activity of Mg-1 wt.% Zn-based alloys containing Nd or Ca during tensile loading. Diffraction patterns collected during tensile loading at 3 temperatures were analyzed using a convolutional multiple whole profile fitting procedure. High activation of nonbasal and pyramidal dislocations was found in the Nd- and Ca-containing alloys. The microstructure evolution after 10% deformation was examined by complementary EBSD measurements. The microstructure evolution was related to the differences in the initial texture and active deformation modes, according to the alloying and temperature. In-grain misorientation axes analysis obtained from the EBSD measurements confirms that the addition of Nd or Ca contributes to the higher activity of prismatic slip. The high activity of prismatic slip leads to a broadening of the basal poles perpendicular to the loading direction and a strengthening of the pole along the loading direction. The overall dislocation density evolution at elevated temperatures is controlled by dynamic recovery and dynamic recrystallization. These thermally activated mechanisms are retarded in the Nd- or Ca-containing alloys.