Multiscale mechanical behavior and microstructure evolution of extruded magnesium alloy sheets: Experimental and crystal plasticity analysis

A phenomenological crystal plasticity finite element (CPFE) model based on Voronoi grains was applied to reproduce basic deformation features of a hot-extruded magnesium alloy sheet under various strain paths. Corresponding experimental investigations, including mechanical tests, electron back scattered diffraction (EBSD) measurements and optical observation, were also carried out as either a validation or a supplement of the numerical results. Predicted average stress-strain responses and texture evolution are in good accordance with measured ones. Furthermore, deformation heterogeneity at the mesoscopic and intergranular scale were investigated based on the proposed model. At the mesoscale, the heterogeneity in the slip-dominated cases tends to develop continuously, whereas the heterogeneity is retarded in twin-favored deformation. At the intergranular scale, it is concluded from the slip-dominated case that a high slip-transfer parameter and high Schmid factors (SFs) of principal slip systems in adjacent grains could accommodate higher local strain.