富镧混合稀土变质过共晶Al-24%Si合金  

Modification Effects of Lan-Rich Mischmetal on Hypereutectic Al-24% Si Alloy

作　　者：李华基[1] 余国勋[1] 胡慧芳[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400030

出　　处：《热加工工艺》2009年第5期33-35,共3页Hot Working Technology

摘　　要：采用富镧混合稀土对过共晶Al-24%Si合金进行变质处理,对其微观组织和力学性能进行了研究。实验结果表明:富镧混合稀土不但能有效变质合金中的初晶硅,使其尺寸减小到40μm左右,形状多为规则的多边形;而且对共晶硅的细化更为明显,在初晶硅周围的共晶组织多为短杆状,部分则呈颗粒状,合金经变质后力学性能得到了明显提高。同时,初步探讨了混合稀土的变质机制。The influences of RE on the microstructure and mechanical properties of hypereutectic Al-24%Si alloy were investigated. Microstructure was examined by SEM.The results show that the addition of La has strong modification effect on the microstructure of hypereutectic Al-24%Si alloy. The average grain size of primary Si phase can be reduced to 40 μm, meanwhile, its modification effect on the eutectic silicon is more obvious, and the eutectic silicons can be transformed into the fine lamella ones. The mechanical properties are improved. The modification mechanism was also discussed.

关 键 词：混合稀土 变质 微观组织 力学性能 变质机制 

分 类 号：TG292[金属学及工艺—铸造]