研究了 Mg-0.5Zr-1.8Zn-xGd(x=0,0.5,1.0,1.5,2.0,2.5,质量分数,％)镁合金经过470℃和10 h固溶处理后的组织、力学性能和耐腐蚀性能.结果表明,Gd含量在0％～2.5％范围内,随着Gd含量增加,合金晶粒尺寸逐渐减小.当Gd含量低于1.5％时,合金元素几乎完全固溶于合金基体中,第二相主要由纳米尺度的(Mg,Zn)3Gd析出颗粒组成.当Gd含量在1.5％～2.5％范围时,合金中出现未固溶的微米尺度的(Mg,Zn)3Gd相,并且该相数量和尺寸随着Gd含量增加而增加.由于组织均匀分布和纳米尺寸的第二相颗粒存在,Mg-0.5Zr-1.8Zn-1.5Gd合金具有优异的力学性能和耐腐蚀性能.在120h浸泡实验中,Mg-0.5Zr-1.8Zn-1.5Gd合金平均腐蚀速率首先降低,然后增加,接着缓慢降低,最后,随着浸泡时间延长,腐蚀速率最终变得稳定.“,”The microstructure,mechanical and anticorrosion properties of Mg-0.5Zr-1.8Zn-xxGd(x=0,0.5,1.0,1.5,2.0,2.5,wt％)alloys were investigated after a solution treatment at 470℃for 10 h.Results indicate that the grain size of the alloy decreases with increasing the Gd content in the range of 0wt％～2.5wt％.When the Gd content is less than 1.5wt％,the alloy elements are more completely dissolved into the alloy matrix,and the second phase is mainly composed of nanoscale(Mg,Zn)3Gd precipitated particle.At the range of 1.5wt％～2.5wt％,the insoluble micron-scale(Mg,Zn)3Gd phase emerges in the alloy,and the number and size of the(Mg,Zn)3Gd phase increase with the Gd content.The Mg-0.5Zr-1.8Zn-1.5Gd alloy shows excellent mechanical properties and anticorrosive ability,which can be attributed to a more homogeneous microstructure and the presence of nanometric secondary phase particles.In the 120 h immersion experiment,the average corrosion rate of the Mg-0.5Zr-1.8Zn-1.5Gd alloy deceases at first,then increases,and then decreases slowly.At last,with the increase of immersion time,it eventually becomes stable.