Y、Gd及固溶处理对AZ31D镁合金组织和性能的影响  

Effects of Y,Gd and Solution Treatment on Microstructure and Properties of AZ31D Magnesium Alloy

作　　者：张美丽[1] 张磊军 付佳乐 马超林 韩茜[1] 李春[1] 窦宝捷 ZHANG Mei-li;ZHANG Lei-jun;FU Jia-le;MA Chao-lin;HAN Xi;LI Chun;DOU Bao-jie(Shaanxi Key Laboratory of Comprehensive Utilization of Tailings Resources,Shangluo University,Shangluo 726000,China;Material Corrosion and Protection Key Laboratory of Sichuan Province,Sichuan University of Science and Engineering,Zigong 643000,China)

机构地区：[1]商洛学院陕西省尾矿资源综合利用重点实验室,陕西商洛726000 [2]四川轻化工大学材料腐蚀与防护四川省重点实验室,四川自贡643000

出　　处：《稀土》2023年第5期31-41,共11页Chinese Rare Earths

基　　金：陕西省教育厅专项科研计划项目(20JK0618);陕西省大学生创新创业训练计划项目(S202011396087);商洛市科技局科学技术研究发展计划项目(2020⁃Z⁃0083);材料腐蚀与防护四川省重点实验室开放基金项目(2021CL17)。

摘　　要：采用光学显微镜、扫描电镜、X射线衍射分析、硬度和耐腐蚀性能测试等手段,研究了不同的混合稀土(Y,Gd)添加量及固溶处理温度对AZ31D镁合金组织和性能的影响。结果表明,添加不同量的混合稀土(Y,Gd)后,AZ31D镁合金均由α⁃Mg、β⁃Mg_(17)Al_(12)和Al_(2)(Y,Gd)相所组成,其中稀土相Al_(2)(Y,Gd)呈颗粒状分布于晶界处,抑制了镁合金晶粒的生长,晶粒得到细化,并使β⁃Mg17 Al12相由网状连续分布变为均匀的断续分布,固溶处理后β⁃Mg_(17)Al_(12)和Al_(2)(Y,Gd)相逐渐发生溶解而进入Mg基体中;随着稀土添加量的增加和固溶温度的升高,镁合金的显微硬度和耐腐蚀性能均呈先增大后减小的变化趋势,经420℃固溶处理后,稀土添加量为2.0%的镁合金耐腐蚀性能最好,稀土添加量为2.5%的镁合金硬度最大,最大硬度值为112.5 HV,相比未添加稀土的铸态镁合金硬度值提高了24.3%。The effects of mixed rare earth(Y,Gd)addition and solution treatment temperature on the microstructure and properties of AZ31D magnesium alloy were studied by means of optical microscope,scanning electron microscope,X⁃ray dif⁃fraction analysis,hardness and corrosion resistance test.The results show that:With the addition of different amount of mixed rare earth(Y,Gd),AZ31D magnesium alloy is composed ofα⁃Mg,β⁃Mg_(17)Al_(12)and Al_(2)(Y,Gd)phases.The rare earth phase Al_(2)(Y,Gd)is distributed in granular form at grain boundaries,which inhibits the growth of magnesium alloy grains and results in grain refinement.After solution treatment,β⁃Mg_(17)Al_(12)and Al_(2)(Y,Gd)phases gradually dissolved into the Mg matrix.With the increase of rare earth addition and solution temperature,the microhardness and corrosion resistance of magnesium alloy in⁃crease first and then decrease.After solution treatment at 420℃,the corrosion resistance of magnesium alloy with rare earth addition of 2.0%is the best,and the hardness of magnesium alloy with rare earth addition of 2.5%is the highest,with the maximum hardness of 112.5 HV.The hardness of as⁃cast magnesium alloy is increased by 24.3%compared with that without rare earth.

关 键 词：镁合金 稀土 固溶处理 显微组织 硬度 耐腐蚀性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]