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

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.