富La、Ce混合稀土和Mg协同作用对Al-9.5Si合金组织演变的影响  

Influence of Synergistic Effect of La-Ce-Rich Mixed Rare Earth and Mg on Microstructure Evolution of Al-9.5Si Alloy

作　　者：李天景[1] 王淼[1] LI Tian-jing;WANG Miao(School of Automotive and Transportation,Yancheng Vocational Institute of Industry Technology,Yancheng 224002,Jiangsu,China)

机构地区：[1]盐城工业职业技术学院汽车与交通学院,江苏盐城224002

出　　处：《矿冶工程》2022年第1期117-121,共5页Mining and Metallurgical Engineering

基　　金：2021年江苏省高等学校自然科学研究面上项目(21KJD430003);2021年江苏省大学生创新创业训练计划立项(202113752010Y);2021年江苏省现代教育技术研究课题(2021-R-92586);盐城工业职业技术学院2020年校级科研课题立项(ygy2004)。

摘　　要：为分析富La、Ce混合稀土(RE)和Mg元素协同作用对Al-9.5Si合金组织演变的影响,采用凝固曲线测试、金相显微镜与扫描电镜观察等手段对不同成分的Al-9.5Si合金样品的形核温度、微观组织形貌等进行了研究。结果表明,相比于单独加入RE或Mg,向Al-9.5Si合金中同时加入1.5%Al-10RE和0.4%Mg使合金变质后,其初生α-Al和共晶形核温度下降约50℃,且过冷度更大;晶粒尺寸和二次枝晶臂间距分别下降93.5%和38.5%,晶粒细化效果显著;共晶Si形貌由片状转变成性能更优的纤维状。In order to analyze the influence of the synergistic effect of La-Ce-rich mixed rare earth(RE)and Mg on the microstructure evolution of Al-9.5Si alloy,the nucleation temperature,microstructure and morphology of Al-9.5Si alloy with different compositions were studied by using solidification curve test,metallographic microscope,scanning electron microscope.The results show that in comparison with the Al-9.5Si alloy with the addition of RE or Mg alone,the modified Al-9.5Si alloy with the addition of 1.5%Al-10 RE and 0.4%Mg has the temperature of primaryα-Al and eutectic nucleation decreased by about 50℃,showing higher degree of undercooling.The grain size and secondary dendrite arm space(SDAS)are decreased by 93.5%and 38.5%,respectively,showing a remarkable crystal-grain refinement.The Si eutectic morphology is transformed from flake to fiber with better performance.

关 键 词：Al-9.5Si合金 稀土 镁 共晶硅 晶粒细化 变质处理 

分 类 号：TG146.21[一般工业技术—材料科学与工程]