The effect of strain heterogeneity on the deformation and failure behaviors of E-form Mg alloy sheets during a mini-V-bending test

Deformation and failure behaviors of E-form magnesium (Mg) alloy sheets were investigated using a mini-V-bending test. The evolution of the microstructure and microtexture of the deformed E-form Mg alloy sheets (before and after failure) was analyzed via an electron back-scattered diffraction (EBSD) technique. Finite element analysis (FEA) was used to capture the heterogeneous distribution of longitudinal-strain components through the thickness direction under mini-V-bending at different punch strokes. The relationships between punch stroke, bending radius and longitudinal-strain at the tension and compression zones were established. EBSD analysis revealed that shear localization by dislocation slip along with compression and double twins were the main deformation mechanisms in the tension zone while tensile twins were a main deformation mechanism in the compression zone in E-form Mg alloy sheets during mini-V-bending. The effect that deformation twinning had on the crack propagation sites in E-form Mg alloy sheets was also investigated. The networks of compression {101¯1} and double {101¯1}−{101¯2} twins in the tension zone of E-form Mg alloy sheets were closely related to the crack propagation during mini-V-bending at near room temperature (RT).