通过光学显微镜、X射线衍射仪(XRD)、描扫电镜(SEM)、微分扫描量热仪(DSC)和力学性能测试等手段,研究了加入质量分数为0%、1%、3%和5%混合稀土对Mg-9Y-0.6Zr(WK90)镁合金组织及性能的影响.结果表明:铸态WK90合金组织由α-Mg基体及少量的共晶组织构成,添加混合稀土后,晶界处的共晶组织明显增多,并由单一共晶形式转变为层状共晶和离异共晶并存;随着混合稀土添加量的增大,共晶组织的种类及数量增多,合金DSC曲线的低熔点吸热峰总面积增大并最终发生分离;混合稀土为3%铸态合金及含混合稀土为1%的挤压态合金分别具有最高的断裂强度,影响合金强度的因素除了晶粒尺寸外,离异共晶组织的分布状态和形貌也是重要的因素. The effects of adding 0%, 1%, 3% and 5% were studied by means of optical microscope, XRD, SEM, DSC and mechanical properties test. % Mixed rare earth on the microstructure and properties of Mg-9Y-0.6Zr (WK90) magnesium alloy.The results show that the as-cast WK90 alloy consists of α-Mg matrix and a small amount of eutectic structure, The eutectic structure obviously increases and the single eutectic form coexists with the layered eutectic and the eutectic eutectic. With the increase of the mixed rare earth content, the types and quantities of the eutectic structure increase, the melting point of the alloy DSC curve The total area of ​​endothermic peak increases and eventually separates; the highest breaking strength of 3% cast rare earth alloy and 1% of mixed rare earth-containing extruded alloy respectively, the factors affecting the strength of the alloy in addition to the grain size, The distribution status and morphology of divorced eutectic is also an important factor.