Achieving high strength in a Mg–Li–Zn–Y alloy by α-Mg precipitation

For ultralight Mg–Li alloys, the improvement of their strength is the most concerned issue. Here we have successfully realized the incredible enhancement of strength in a Mg-8.5Li-7.5Zn-1.5Y cast alloy via simple heat treatment. The yield strength of 271.4 MPa is obtained, and the yield strength increment is as high as 173 MPa due to heat treatment, which is rarely reported previously in Mg alloys. The formation of profuse needle-shaped α-Mg precipitates distributed uniformly in β-Li matrix is mainly responsible for such a large improvement of yield strength. The new finding for strengthening way is expected to contribute to the design of high-performance Mg–Li alloys.