Texture development and dislocation activities in Mg-Nd and Mg-Ca alloy sheets
Chen Ha, Jan Bohlen, Xiaohua Zhou, H.‐G. Brokmeier, Karl Ulrich Kainer, Norbert Schell, Dietmar Letzig, S. Yi
Abstract
Texture modification during sheet rolling appears differently in binary Mg-RE (rare-earth) or Mg-Ca alloy, compared to their ternary counterparts containing Zn. The differences in texture development and the active deformation mechanisms under tensile loading were investigated in the binary alloys. These analyses are based on in-situ synchrotron experiments and electron backscatter diffraction measurements to reveal direct experimental evidence of the texture development and the active deformation mechanisms. Higher activations of nonbasal <a> and pyramidal <c+a> dislocations were found in the Nd or Ca containing Mg alloys, compared to the Mg-Zn alloy. The texture development shows an obvious feature, which is a broadening of the basal pole intensity distribution perpendicular to the loading direction and a strengthening of the <101¯0> pole at the loading direction in all examined sheets. This texture development relates to the higher activation of prismatic <a> slip. The addition of Zn in the Mg-RE or Mg-Ca alloys further promotes the activation of nonbasal <a> and pyramidal <c+a> dislocations. This enhanced prismatic <a> slip in the Zn containing ternary alloys is confirmed by EBSD misorientation analysis.