Preparation of high strength Mg–Li–Zn–Y alloy by MgLi2Zn precipitation

Abstract

For ultralight Mg–Li alloys, the improvement of strength is the most concerned issue. In this work, we successfully realize the incredible enhancement of strength in the Mg-8.5Li-7.5Zn-1.5Y alloy via a series of preparation processes, and the excellent tensile properties containing high yield strength of 312.4 MPa and good elongation of 14.2 % are obtained. Yield strength increment is as high as 213 MPa through deformation processing, which is rarely reported in Mg–Li alloys. Qualitative and quantitative studies reveal that the dislocation cutting of semi-coherent MgLi2Zn nano-precipitates is mainly responsible for such a high yield strength. The new finding for strengthening way is expected to contribute to the design of high-performance Mg–Li alloys.