Unraveling the effect of Zn and Ca additions on tensile properties and bendability of a new formable Mg-Al-Mn alloy sheet

• AM and AZXM alloy sheets with weak texture and similar grain size were fabricated. • Both the sheets exhibited similar ductility and bendability. • AZXM alloy sheet showed large work-hardening. • AZXM alloy sheet did not show enhanced activity of prismatic slip. • Al 2 Ca phase promoted crack formation and propagation. This work aims to reveal the actual effect of Zn and Ca additions on tensile properties and bendability of a recently designed Mg-3Al-0.2Mn (mass %, AM30) sheet with high formability. We fabricated AM30 and Mg-3Al-0.8Zn-0.5Ca-0.2Mn (mass %, AZXM3100) sheets with weakly aligned (0001) poles. Their deformation behaviors were thoroughly investigated using electron backscattered diffraction and crystal plasticity simulation. We found that the Zn and Ca additions were not effective in improving the ductility and formability. Both the sheets showed large elongation to failure of ∼30 % in tension, and their maximum bending angles during three-point bending were ∼90°. In-depth characterization of the deformation behaviors revealed that the Zn and Ca additions slightly facilitated tensile twinning, and the activity of the non-basal prismatic slip did not increase in the AZXM3100. Moreover, the Al 2 Ca phase, which was formed in the AZXM3100, promoted the formation and propagation of cracks by concentrating plastic deformation. Therefore, ductility and formability could not be improved even after the Zn and Ca additions.