Correlation between shear punch and tensile measurements for an AZ31 Mg alloy processed by equal-channel angular pressing

Abstract

An AZ31 magnesium alloy was extruded and then processed by equal-channel angular pressing (ECAP) at 200◦C for 1, 2, and 4 passes. The grain structure was refined from 20.2 to 1.6 µm after 4 passes. The shear punch testing (SPT) technique and uniaxial tensile tests were employed to evaluate the mechanical properties of the extruded and ECAP samples. The 4 pass ECAP alloy showed lower yield stress and higher ductility compared to the as-extruded condition, indicating that texture softening overcame the strengthening effects of grain refinement. The same trends in strength and ductility were also observed in shear punch testing. Three different linear correlations between the shear data and tensile data were established for ductility, yield stress, and ultimate strength. It is shown that SPT is a useful method for evaluating the mechanical properties of small quantities of fine-grained materials processed by ECAP.