Effect of Cu on the Superplastic-like Behavior of Coarse-Grained Al-Mg Alloys

In this study, the effect of Cu content on the superplastic-like behavior of Al-Mg alloys in coarse grain size condition has been studied. Five hot-rolled Al-Mg alloys with different Cu concentrations (0.5, 1.0, 1.5, and 2.0 wt.%) and without Cu were prepared. Tensile test specimens were machined parallel to the rolling direction. High-temperature elongation to failure tests were performed under a constant cross-head speed condition at different strain rates and temperatures. Grain size refinement is observed as Cu addition increases. Maximum tensile elongation of 373% could be achieved in the Al-4.5%Mg-1.5%Cu alloy with an average grain size of 28 μm at 500 °C and 1 × 10−2 s−1. Grain size refinement after superplastic deformation was also observed.