冷却速率对Nd变质的Al-6Mg-4Si合金中Mg2Si的影响  

Effects of Cooling Rate on Mg2Si in Nd Modified Al-6Mg-4Si Alloy

作　　者：王鑫[1] 程艳艳 牛玉[1] 刘祥玲 姜峰[1] Wang Xin;Cheng Yanyan;Niu Yu;Liu Xiangling;Jang Feng(College of Mechanical and Electrical Engineering,Jilin Institute of Chemical Technology;Nanchang Institute of Technology,School of New Energy and Environmental Engineering)

机构地区：[1]吉林化工学院机电工程学院,吉林省吉林市132022 [2]南昌理工学院新能源与环境工程学院

出　　处：《特种铸造及有色合金》2022年第10期1270-1273,共4页Special Casting & Nonferrous Alloys

基　　金：吉林化工学院资助项目(2019018)。

摘　　要：研究了冷却速率及Nd变质处理对亚共晶Al-11MgSi合金组织的影响。结果表明,Al-11MgSi合金组织由初生α-Al相和α-Al+MgSi共晶相组成。随着模具冷却速率提高,共晶温度降低,过冷度增加,组织中初生α-Al相面积比逐渐降低,MgSi共晶相由粗大的片层状变为细小的纤维状,MgSi相二次枝晶间距减小,组织细化;经0.4%的Nd变质后,随着冷却速率提高,在凝固过程中,变质剂的加入形成MgSi共晶团局部熔体过冷,提高形核率,Al-11MgSi合金中共晶团中MgSi呈团絮状均匀分布。The effects of cooling rate and Nd modification on the microstructure of hypoeutectic Al-11 MgSi alloy were investigated. The results indicate that the microstructure of hypoeutectic Al-11 MgSi alloy is composed of primary α-Al and(α-Al+MgSi) phase. With the increase of the cooling rate of the mould, the eutectic temperature is decreased and the undercooling is increased, where the area fraction of primary α-Al phase is gradually decreased, and the MgSi eutectic phase is converted from coarse lamellar to fine fibrous. Moreover, the secondary dendrite spacing of MgSi phase is decreased and the microstructure is refined. After 0.4% Nd modification, with the increase of cooling rate, the addition of modifier leads to the partial melt undercooling of MgSi eutectic during solidification, improving the nucleation rate. MgSi is uniformly distributed in form of flocculent in eutectic of Al-11 MgSi alloy.

关 键 词：Al-11Mg2Si 冷却速率 Nd变质 MG2SI 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG244.3[金属学及工艺—金属材料]