Varying strain rates and elevated temperatures effects on the mechanical properties of AZ31B magnesium alloy

Abstract

This study investigates the monotonic tensile behavior of magnesium (Mg) alloy AZ31B across a temperature range from ambient (25 °C) to elevated (up to 300 °C) with varying strain rates (SR) (1.5 × 10−2 to 1.5 × 10−4 s−1). Mechanical properties such as ultimate tensile strength ( σu), tensile yield strength ( σy), strain to failure ( εf), plastic anisotropy ( r-value), strain rate sensitivity ( m) and strain hardening exponent ( n) were investigated in this study for these strain rates. As the temperature increased from 25 to 300 °C, the following changes in mechanical properties were observed: the yield strength ( σy) decreased by 84.50%, the ultimate tensile strength ( σu) decreased by 87%, the modulus of elasticity ( E) decreased by 63.0%, and the elongation increased by 72.0%. The reduction factors (RF) were proposed for the above-mentioned mechanical properties for varying temperature ranges. The impact of varying temperatures and strain rates on fracture surfaces was investigated using field emission scanning electron microscopy (FE-SEM). The results revealed the presence of tenacity nets, cleavage patterns, and an increasing number of dimples as temperatures increased.