Superplasticity in an ultrafine-grained Al-Mg-Sc alloy produced by equal-channel angular pressing

An Al-3% Mg-0.2% Sc alloy was subjected to equal-channel angular (ECA) pressing to produce a grain size of similar to 0.2 mu m. Static annealing experiments showed that it was possible to retain a very small grain size at temperatures up to 673 K for an annealing time of 1 hour. Large tensile ductilities were observed after ECA pressing, including elongations of >600% and >1000% when testing with an initial strain rate of 3.3 x 10(-2) s(-1) at temperatures of 573 and 673 K, respectively, The results demonstrate the potential for using a scandium addition in Al-based alloys in order to retain an ultrafine grain size at elevated temperatures and thereby to achieve superplastic ductilities.