Influence of the combined addition of Y and Nd on the microstructure and mechanical properties of Mg–Li alloy

• With combined addition of Y and Nd in Mg–5Li–3Al–2Zn, there exist α, AlLi, Al11Nd3 and Al2Y phases.
• When the content of Y and Nd is 1.2% and 0.8%, respectively, the grain refining effect is the best.
• When the content of Y and Nd is 1.2% and 0.8%, respectively, the mechanical properties are the best.
• Y and Nd have the synergistic effect in Mg–5Li–3Al–2Zn–1.2Y–0.8Nd.

Y and Nd are simultaneously added into Mg–5Li–3Al–2Zn alloy. It is found that there exist the phases of α-Mg, AlLi, Al11Nd3 and Al2Y in the alloys. When the contents of Y and Nd are 1.2% and 0.8%, respectively, the grain is the finest with an average size of 30 μm, and the tensile strength of the alloy reaches 231 MPa, the elongation reaches 16%. When the ratio of Y to Nd is 1.2:0.8, there is a synergistic strengthening effect.