固溶处理对Sr变质镁合金中共晶Mg_2Si的影响  

Effects of Solution Treatment on Eutectic Mg_2Si in Magnesium Alloys Modified with Sr

作　　者：任磊[1] 郭学锋[1] 崔红保[1] 

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454000

出　　处：《铸造》2014年第7期642-646,共5页Foundry

基　　金：河南省科技攻关项目(102102210031);河南省教育厅自然科学项目(2010A430008)

摘　　要：通过重力铸造制备了Sr变质Mg-2Al-Zn-Si合金,研究了Sr对共晶Mg2Si的变质效果,尤其是固溶处理对Sr变质Mg-2Al-Zn-Si合金中共晶Mg2Si的影响,分析了固溶处理对共晶Mg2Si的变质机理。结果表明,Sr对共晶Mg2Si相有明显的变质效果,Mg2Si由粗大汉字状变质为细小棒状或颗粒状;固溶处理对Mg-2Al-Zn-Si合金中共晶Mg2Si有显著的细化作用,汉字状Mg2Si退化为均匀圆球状,但对Sr变质后Mg-2Al-Zn-Si合金中共晶Mg2Si相的球化作用很差。固溶变质机理为Sr固溶于共晶Mg2Si相,改变Mg2Si相的优先生长方向及抑制了Si原子的扩散。Mg-2Al-Zn-Si alloy modified with different contents of Sr addition was prepared through the gravity casting. The effects of Sr addition on the modification ofeutectic Mg2Si crystals, especially solution treatment on eutectic Mg2Si in Mg-2Al-Zn-Si alloy modified with Sr addition were investigated. The modification mechanism of solution treatment on eutectic Mg2Si phases modified with and without Sr addition was analyzed. The research results indicate that eutectic Mg2Si phases are effectively modified by Sr addition, namely, their morphologies change from Chinese script shape to short pole or granular shapes, but the spheroidizing of eutectic Mg2Si crystals in Mg-2Al-Zn-Si alloy modified with Sr addition becomes worse. The modification mechanism of solution treatment on eutectic Mg2Si phases modified with Sr is the preferred growth manner of Mg2Si and depressed diffusion of Si atom by the incorporated Sr in eutectic Mg2Si.

关 键 词：镁合金 共晶Mg2Si 固溶处理 变质 

分 类 号：TG146.22[一般工业技术—材料科学与工程]