稀土对Al-3.0wt.%Mg合金微观组织结构的影响和作用机理  

Effect of Rare Earth on Microstructure of Al-3.0wt.%Mg Alloy and Its Action Mechanism

作　　者：张欣[1,2] 王泽华 邵佳[1] 郭珈旭[1] 杨光恒 ZHANG Xin;WANG Ze-hua;SHAO Jia;GUO Jia-xu;YANG Guang-heng(College of Mechanics and Materials,Hohai University,Nanjing 211100,Jiangsu,China;Nantong Ocean and Ofishore Engineering Research Institute,Hohai University,Nantong 226300,Jiangsu,China)

机构地区：[1]河海大学力学与材料学院,江苏南京211100 [2]南通河海大学海洋与近海工程研究院,江苏南通226300

出　　处：《铸造》2020年第1期51-57,共7页Foundry

基　　金：南通市科技计划项目(JC2018047);中央高校基本科研业务费项目(2018B02514)。

摘　　要：通过光学显微镜(OM)、扫描电子显微镜(SEM)和能谱分析仪(EDS)观察分析了不同混合稀土(37.3wt.%La,61.5wt.%Ce)含量的Al-3.0wt.%Mg合金微观组织结构和第二相三维形态,并研究了稀土元素对该合金微观组织影响和作用机理。结果表明:适量的稀土能够细化Al-3.0wt.%Mg合金的晶粒、枝晶和骨骼状富铁第二相,具有优秀的除杂作用,并显著提高合金的性能;过量的稀土会使合金晶粒和枝晶变得粗大,并在晶界处形成大量粗大的骨骼状Al4Ce/Al4La相。In this study, the microstructure and secondary phase morphology of Al-3.0 wt.%Mg alloy containing rare earth(RE) were characterized by optical microscopy, scanning electron microscopy and energy-dispersive spectroscopy. The results indicate that the addition of proper amount of RE into Al-3.0 wt.% Mg alloy can refine the grains, dendrite and skeletal Fe-rich phase;excessive addition of RE will coarsen the grain size, enlarge the dendrite spacing, and promote the formation of skeletal Al4 Ce/Al4 La phase at the grain boundary.

关 键 词：Al-3.0wt.%Mg合金 微观组织 混合稀土 深腐蚀 

分 类 号：TG113.12[金属学及工艺—物理冶金]