Unveiling the bending deformation behaviors of Mg alloys with tilted textures through a biaxial tension analysis approach

This study investigates the three-point bending behavior of rolled AZ31 magnesium alloy specimens with different initial texture orientations by analyzing the activation of deformation mechanisms through Schmid factor (SF) calculations under both uniaxial and biaxial stress states. Three specimen types—BD90, WD90, and LD90—were machined from the same rolled plate such that the basal texture was oriented perpendicular to the bending direction (BD), width direction (WD), and longitudinal direction (LD), respectively. Despite having identical initial microstructures, the failure bending strains varied: WD90 exhibited the highest strain (16.2%), followed by BD90 (12.3%) and LD90 (12.4%). Electron backscatter diffraction revealed that {10−12} twinning was most pronounced in BD90, moderate in WD90, and limited in LD90. However, SFs calculated under uniaxial tension did not correspond with the experimentally observed twinning trends. In contrast, SFs derived under biaxial tension accurately reflected both the twinning and basal slip behavior, as well as the overall bending performance. These findings demonstrate that SF analysis under biaxial stress provides a more reliable framework for understanding and predicting the deformation behavior of textured magnesium alloys during bending.