Microstructure and mechanical properties of Mg–8Li–2Zn–0.5(Ce, Y) alloys

0.5 wt.% Ce and Y were added into the alloy of Mg–8Li–2Zn, respectively. The different behaviors of Ce and Y in the alloy were investigated. Results show that, Ce and Y can both refine the α phase, and the α phase was spheroidized. Two kinds of compounds exist in the alloy when the alloy contains Ce/Y. They are Zn2Ce and Mg6Y, respectively. Zn2Ce mainly distributes at the grain boundary of the alloy with the shape of blocky. Mg6Y mainly distributes in the inner place of grains with the shape of granular. The size of Zn2Ce is much larger than that of Mg6Y. Y and Ce are both favorable for the improvement of strength, and the effect of Y is more obvious. The addition of Ce makes the elongation of the alloy become poor, while the addition of Y can increase the elongation of the alloy.

Research highlights▶ Ce and Y can both refine the α phase in the alloy, and the α phase was spheroidized. ▶ Two kinds of compounds exist in the alloy when the alloy contains Ce/Y. ▶ They are Zn2Ce and Mg6Y, respectively. ▶ Zn2Ce mainly distributes at the grain boundary of the alloy with the shape of blocky. ▶ Mg6Y mainly distributes in the inner place of grains with the shape of granular. ▶ The size of Zn2Ce is much larger than that of Mg6Y. ▶ Y and Ce are both favorable for the improvement of strength, and the effect of Y is more obvious. ▶ The addition of Ce makes the elongation of the alloy become poor, while the addition of Y can increase the elongation of the alloy.