Microstructural study of strain localization in hot compressed Mg–3Al–1Zn alloy

The evolution of microstructure during strain localization in hot compressed Mg–3Al–1Zn alloy is studied. Strain localization is caused by the formation of a macro-shear band (macro-SB), which consists of shear bands (SBs), and a matrix with a high fraction of dynamically recrystallized (DRXed) fine grains. SBs consist of DRXed fine grains, are in sheet form, parallel to the transverse direction (TD) and incline ∼30° to the rolling plane of the plate. Basal plane normal of DRXed fine grains in SBs rotates about the TD away from the normal direction (ND) during compression. Due to geometric softening, strain is localized within SBs, which leads to further strain localization in a macro-SB. The deformation in a SB is contributed by grain boundary sliding and dislocation slip.

Research highlights▶ In Mg–3Al–1Zn strain localization is caused by shear bands. ▶ SBs consist of dynamically recrystallized fine grains. ▶ The deformation in a SB is contributed by grain boundary sliding and dislocation slip.