Developing superplastic properties in an aluminum alloy through severe plastic deformation

Equal-channel angular (ECA) pressing is a processing procedure which subjects a material to severe plastic deformation. Tests were conducted on a commercial cast aluminum alloy to evaluate the properties associated with samples subjected to three different ECA pressing procedures. The results show that all three procedures lead to an ultrafine microstructure and each procedure is capable of producing samples which exhibit high strain rate superplasticity. Optimum superplastic properties were achieved in samples subjected to ECA pressing to a strain of similar to 12. Under these conditions, the measured elongations to failure at a temperature of 673 K were 1210 and 950% at strain rates of 10(-1) and 1 s(-1), respectively. (C) 1999 Elsevier Science S.A. All rights reserved.