Superplastic behavior of the Al-Mg-Sc-Zr alloy with bimodal structure processed by equal channel angular pressing and subsequent rolling

Microstructure and superplastic (SP) behavior of the commercial 1570C aluminum alloy was studied after equal channel angular pressing (ECAP) at T = 325°C with a strain of e ∼ 3 and subsequent rolling with reductions about 80% at the same and room temperature. Even containing the bimodal structure with the fraction of ultrafine grains of about 0.3, formed by ECAP, the alloy demonstrated high strain rate superplasticity with maximum elongations-to-failure exceeding 2500% at 520°C and initial strain rate of 1.4×10−2 s−1. In spite of the difference in type and parameters of microstructure processed in the rolled states, the alloy SP behavior with elongations up to 3000% was observed at close optimum temperature-strain rate conditions.