High temperature tensile behavior of Mg-2Al and Mg-6Al alloys

Abstract

Abstract Effects of 2 and 6 wt.% Al additions on the high temperature tensile behavior of Mg were investigated. Elongation-to-failure tensile tests were conducted at four temperatures (300, 350, 400, and 450 °C) and two strain rates (10− 2 and 10−3 s−1) to study tensile ductility. Strain-rate-change tensile tests were conducted at the same temperatures over a strain-rate range of 5 × 10−5–2 × 10−2 s−1. The experimental data show that the coarse-grained alloys exhibit elongations of about 100% at 450 °C and 10−3 s−1, and the Mg-6Al alloy presents a significant elongation improvement at 400 and 450 °C. Compared with pure Mg, Al additions of 2 and 6 wt.% effectively reduce the stress exponent, which decreases with increasing Al content. The reduced stress exponents may result from solute-drag creep created by Al atoms released from dissolution of Mg17Al12 phase at high temperatures.