Microstructurally-driven Investigation of Strain Localization in Wrought Magnesium Alloy

Despite frequent observations of strain localization, the formation of shear bands, their development, and overall contribution to rolling and recrystallization textures is still not understood from both material and mechanics perspectives. To understand microstructure-specific mechanisms responsible for local (micro) plasticity, as well as shear band formation and development in magnesium alloys, full field strain measurements provided by Digital Image Correlation (DIC), were coupled with Acoustic Emission (AE) monitoring. Mechanical testing was performed to samples with two different rolling sheet textures. Controlled specimen geometry provided an a priori defined strain localization zone that assisted in minimizing the unknowns. Electron back scattered diffraction (EBSD) results on the role of twinning in shear band formation and associated strain measurements are reported. This provided the means to implement a microstructurally-validated and feature-based AE analysis and classification of extension twinning. Such quantified information demonstrated the effect of texture in shear band formation and provided evidence on possible slip-twin interactions at early stages of plasticity in Mg alloys. The reported results create the framework for further in situ investigations of microstructure evolution and its role in Mg micro-plasticity, while it further provided results that could be used to validate hypotheses in multiscale computational modeling approaches.