稀土Sm对Al-7Si-0.3Mg合金微观组织的影响  

Effect of rare earth Sm on microstructure of Al-7Si-0.3Mg aluminum alloy

作　　者：董衍蘅 贾志宏[1,2] 温柏杨 刘莹莹[1,2] 刘庆[1,2] 吴俊子[3] 高斯娥 DONG Yan-heng;JIA Zhi-hong;WEN Bo-yang;LIU Ying-ying;LIU Qing;WU Jun-zi;GAO Si-e(College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China;Electron Microscopy Center,Chongqing University,Chongqing 400044,China;Baotou Research Institute of Rare Earths,Baotou 014030,China)

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]重庆大学电子显微镜中心,重庆400044 [3]包头稀土研究院,包头014030

出　　处：《中国有色金属学报》2020年第3期479-488,共10页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金面上项目(51871035);中央高校基本科研业务费项目(2018CDGFCL00022)。

摘　　要：采用金相显微镜(OM)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)和差示扫描量热法(DSC)等研究不同含量稀土Sm对Al-7Si-0.3Mg合金微观组织的影响。结果表明:添加Sm元素之后,合金的二次枝晶间距相比基础合金的明显减小;稀土Sm可以显著细化片层状的共晶硅,Sm元素主要形成Al2Si2Sm相。从能量角度,Sm可优先与P形成SmP相,可能会抑制AlP相的形成,减弱其促进共晶硅形核的效能。随着Sm元素含量的增加,Al-Si共晶反应的过冷度逐渐增大。The effect of different contents of rare earth Sm on the microstructure of Al-7Si-0.3Mg alloy was investigated by using multiscale microstructure characterization techniques(i.e.,OM,SEM,TEM),XRD and DSC analyses.The results show that the secondary dendrite arm spacing in the Al-7Si-0.3Mg is significantly reduced by Sm addition.Plate-like eutectic Si is refined obviously.Sm is mainly consumed through the formation ofAl2Si2Sm phase.According to the formation energy,the Sm P phase easily forms,which could inhibit the formation of AlP phase,and deteriorate the function of AlP phase to eutectic Si in Al alloys.The undercooling of the Al and Si eutectic reaction increases with increasing the Sm content.

关 键 词：Al-7Si-0.3Mg铝合金 稀土Sm 微观组织 细化机理 

分 类 号：TG146.2[一般工业技术—材料科学与工程]