The High-Strain-Rate Constitutive Behavior and Shear Response of Pure Magnesium and AZ31B Magnesium Alloy

The high-strain-rate response of pure magnesium and AZ31B magnesium alloy is examined in compression and in a forced shear-loading top-hat configurations. Compression specimens loaded in the direction normal to the plane of the rolled plate (TT) display higher-strain-rate sensitivity than specimens that were loaded within the plane of the rolled plate (IP). This effect is more pronounced for pure magnesium as compared to the alloy, due to increased twinning in the IP direction as compared to the TT. Additionally, top-hat shear specimens loaded at high strain rates are observed to display stable deformation during loading, and the development of adiabatic shear bands is not observed. We hypothesize that this result is due to adiabatic heating during deformation, which enhanced the contribution of slip, lessened the role twinning, and possibly activated dynamic recrystallization processes, thus, preventing the formation of distinct shear bands.