Yb和Al-Ti-B复合变质对过共晶Al-Si铸造合金组织和性能的影响  

Influence of Yb and Al-Ti-B Complex Modification on Microstructure and Performance of Hypereutectic Al-Si Casting Alloys

作　　者：李庆林[1] 住玉乾 李进宝[1] 李斌强[1] 刘建军[1] 刘德学[1] 兰晔峰[1] 夏天东[1] Li Qinglin;Zhu Yuqian;Li Jinbao;Li Binqiang;Liu Jianjun;Liu Dexue;Lan Yefeng;Xia Tiandong(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metal,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050

出　　处：《稀有金属材料与工程》2020年第6期1915-1924,共10页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51561021)。

摘　　要：采用光学显微镜、扫描电子显微镜、电子探针研究了不同比例的稀土Yb和Al-5Ti-B复合变质剂对过共晶Al-20Si合金显微组织与性能的影响。结果表明,Al-20Si合金中添加质量分数0.5%Yb和0.3%Al-5Ti-1B复合变质剂使得粗大的多边形状、块状和五瓣星状初生Si变质为细小块状,共晶Si由粗大的片状或针状结构变质为细小颗粒或者纤维结构,而且粗大的α-Al枝晶被细化为等轴枝晶。然而,当Al-5Ti-B变质剂含量达到0.4%时,初生Si和共晶Si出现粗化现象。力学性能测试结果表明,联合添加0.5%Yb和0.3%Al-5Ti-B后,合金的抗拉强度和延伸率分别增加了83.7%和92.1%。The microstructure evolution and mechanical properties of hypereutectic Al-20Si alloy containing rare earth Yb and Al-5Ti-1B refiner were investigated.The microstructures of the samples were characterized by optical microscopy,scanning electron microscopy,and electron probe microanalysis.Microstructural analysis demonstrates that the primary Si is significantly refined from a coarse polygonal,platelet-like or star-like shape into a fine blocky shape;the eutectic Si structure is modified from a coarse platelet-like/needle-like structure into fine particles or a fibrous structure;and the coarseα-Al dendrites are refined into fine equiaxed dendrites after addition mass fraction of 0.5%Yb and 0.3%Al-5Ti-1B complex.However,the primary and eutectic Si phases become coarser when the content of Al-5Ti-1B refiner reaches 0.4%.The mechanical properties of the Al-20Si alloy with different modifiers and different modifier concentrations were investigated by the tensile test.The results show that after combined addition of 0.5%Yb and 0.3%Al-5Ti-B the ultimate tensile strength and elongation of the prepared sample increase by 83.7%and 92.1%,respectively.

关 键 词：过共晶Al-20Si合金 初生SI 共晶Si 稀土Yb Al-5Ti-1B变质剂 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]