中文摘要：

在CO2＋SF6气体保护条件下感应熔炼制备了不同Y含量的AZ61-x Y（x=0,0.5,1,1.5,2）镁合金,利用光学金相显微镜（OM）、扫描电镜（SEM）、X射线衍射分析（XRD）、能谱分析（EDS）和拉伸及蠕变力学性能测试手段研究了Y添加对AZ61合金显微组织和力学性能的影响。结果表明：合金中添加适量的稀土元素Y后,AZ61合金的显微组织得到明显的细化,合金中除了存在α-Mg和Mg17Al12相,还出现了块状析出相Al2Y。适量的Y显著提高了合金在室温和高温时的强度和塑性,同时合金在150℃/70MPa条件下的抗蠕变性能也有显著的提升。

英文摘要：

The AZ61-x Y（ x = 0,0. 5,1,1. 5,2） magnesium alloy were prepared through induction melting under the CO2＋ SF6 gas protection condition. Effect of Y addition on the microstructure and mechanical properties of AZ61 alloy was investigated by OM,SEM,XRD,EDS,tensile and creep tests. The results showed that the microstructure of AZ61 alloy was markedly refined by the addition of Y. Apart from the α-Mg and Mg17Al12 phases in the microstructure of AZ61-1. 5Y alloy,new block Al2 Y phase could be found also. An appropriate amount addition of Y could significantly improve the strength and ductility of AZ61 magnesium alloy at room temperature and high temperature. And the creep properties of AZ61 alloy at 150 ℃ /70 MPa condition were significantly improved with the Y addition also.