Effects of Rolling Reductions on Microstructure Evolution and Mechanical Properties of Mg–8Li–1Al–0.6Y–0.6Ce Alloy

Abstract

The effects of rolling reductions on microstructure evolution and mechanical properties of as‐rolled Mg–8Li–1Al–0.6Y–0.6Ce alloys are studied. When the thickness reduction increases from 30% to 90%, α‐Mg phase is elongated along the rolling direction, and the aspect ratio of fiber structure increases. At the same time, the volume fraction of β‐Li phase increases, because part of α‐Mg phase transforms into β‐Li phase. When the rolling reduction is 70%, the alloy shows the best comprehensive performance with the ultimate tensile strength (UTS) of 238 MPa and the elongation of 24%, mainly caused by fine‐grain strengthening and strain hardening. During the rolling process, β‐Li phase is deformed preferentially and subsequently drives the deformation of α‐Mg phase. Then some twins are generated, which promote the dislocation slip, thereby promoting the deformation coordination.