轻-重稀土混合添加对Al-Si-Mg合金显微组织和力学性能的影响  

Effect of mixed addition of light and heavy rare earth elements on microstructure and mechanical properties of Al⁃Si⁃Mg alloy

作　　者：曾祥军 史志铭[1] 赵鸽[1] 廉浩 刘佳成 Zeng Xiangjun;Shi Zhiming;Zhao Ge;Lian Hao;Liu Jiacheng(School of Materials Science and Engineering,Inner Mongolia University of Technology,Hohhot Inner Mongolia 010051,China)

机构地区：[1]内蒙古工业大学材料科学与工程学院,内蒙古呼和浩特010051

出　　处：《金属热处理》2024年第8期36-41,共6页Heat Treatment of Metals

摘　　要：采用光学显微镜、扫描电镜/能谱仪和力学性能测试仪研究了轻-重稀土(La、Ce、Gd、Ho、Er)混合添加对Al-6.9Si-0.36Mg合金显微组织和力学性能的影响。结果表明,当稀土总添加量为0.1%时,铸态合金中α-Al晶粒细化效果明显,当稀土总添加量为0.4%时,对共晶Si相的改善效果明显,共晶Si相由粗大针状转变为颗粒状。经T6热处理后,共晶Si相进一步转变为细小颗粒状并均匀分布于基体中,降低了对基体的割裂作用。稀土总添加量为0.4%时,T6热处理态合金的力学性能最佳,抗拉强度、断后伸长率和硬度分别达到285.4 MPa、7.0%和89.2 HBW。Effect of mixed addition of light and heavy rare earth elements(La,Ce,Gd,Ho,Er)on the microstructure and mechanical properties of Al⁃6.9Si⁃0.36Mg alloy was studied by using optical microscope,scanning electron microscope/energy dispersive spectroscopy,and mechanical property testers.The results show that the refinement effect ofα⁃Al grains in the as⁃cast alloy is significant with total rare earth addition of 0.1%.As total amount of rare earth added is 0.4%,the improvement effect on the eutectic Si phase is significant,and the eutectic Si phase changes from coarse needle⁃shaped to granular.After T6 heat treatment,the eutectic Si phase further transforms into small particles and uniformly distribute in the matrix,reducing the cutting effect on the matrix.When the total amount of rare earth elements added is 0.4%,the mechanical properties of the T6 heat treated alloy are the best with tensile strength of 285.4 MPa,elongation after fracture of 7.0%,and hardness of 89.2 HBW.

关 键 词：稀土 AL-SI-MG合金 显微组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]