Grain refinement and mechanical properties improvement of AZ31 Mg alloy sheet obtained by two - stage rolling

Abstract

A simple process named two - stage rolling was proposed and investigated to obtain a fine-grained microstructure of AZ31 Mg alloy sheet. The first stage rolling is deformed at 773K with a large reduction by single pass, while the second stage process is a multi-pass warm rolling deformed at 573K. Microstructure and texture were measured on sheets subjected to rolling experiments of different reductions, and the tensile test was also carried out. After the two-stage rolling and subsequent annealing, reductions as large as 89% were achieved without surface cracking; the AZ31 alloy sheet exhibits a homogenous microstructure with fine grains and weak basal texture, where the final average grain size is stabilized around 3µm; thus, it shows the high strengths and good ductility.