The synergetic effects of strontium (Sr) and rare earth elements (RE) on the modification of the microstructure and enhancement of the mechanical properties of as-cast Mg–9Al–1Zn alloy were studied. Based on the microstructural analysis, phase identification, and tensile tests, it was revealed that the combined RE and Sr addition results in superior mechanical properties compared to those of solo additions of RE or Sr. This was related to both morphological enhancement of the β-Mg₁₇Al₁₂ intermetallics notably by RE towards the disappearance of the intergranular network and modification of the Al₁₁RE₃ particles by Sr. The enhancement of tensile properties was achieved by increasing the RE/Sr ratio in the Sr-RE containing alloys and the best combination of mechanical properties was observed for the Mg–9Al–1Zn-0.9RE-0.1Sr alloy. Owing to the dissolution of the β phase and solid solution strengthening effect of Al, the tensile properties of the Mg–9Al–1Zn-0.9RE-0.1Sr alloy were enhanced by homogenization treatment. Moreover, the hot extrusion process remarkably augmented the tensile properties by combined effects of grain refinement and fracturing and distributing the intermetallic particles.

研究了锶（Sr）和稀土元素（RE）协同作用对铸态Mg-9Al-1Zn合金显微组织的改变和力学性能的增强的作用。通过微观结构分析，相鉴定和拉伸试验，发现与单独添加RE或Sr相比，结合使用RE和Sr可获得更好的机械性能，这与β- Mg ₁₇ Al ₁₂金属间化合物主要通过稀土向晶间网络的消失和Al ₁₁ RE _3的改性通过增加含Sr-RE的合金中的RE / Sr比可以提高抗拉性能，并且观察到Mg-9Al-1Zn-0.9RE-0.1Sr合金具有最佳的机械性能组合。由于β相的溶解和Al的固溶强化作用，通过均质处理提高了Mg-9Al-1Zn-0.9RE-0.1Sr合金的拉伸性能。此外，热挤压工艺通过晶粒细化和断裂以及分布金属间颗粒的综合作用显着提高了拉伸性能。