高含量自生Mg_2Si/Mg-9Al复合材料组织与形成机理  

Microstructure and Solidification Mechanism of Mg_2Si/Mg-9 Al Matrix Composites with High Content In-Situ Mg_2Si Particles

作　　者：卢春辉[1] 尹健[1] 刘飞[1] 

机构地区：[1]南昌航空大学航空制造工程学院

出　　处：《特种铸造及有色合金》2016年第11期1194-1197,共4页Special Casting & Nonferrous Alloys

基　　金：江西省自然科学基金资助项目(20151BAB216002);江西省教育厅科学技术研究项目(GJJ150708)

摘　　要：在Mg-9Al合金中添加3%~9%的Si,采用高频感应加热熔炼、随炉冷却凝固,获得了Mg_2Si含量高达10%~30%的Mg-9Al基复合材料。利用光学显微镜、扫描电镜、能谱分析、X射线衍射分析及差热分析（DTA）,研究了复合材料的凝固组织与形成机理。结果表明,复合材料都是由Mg_2Si、Mg17Al12和α-Mg等3种相组成,而Mg_2Si和Mg17Al12含量随Si含量增加而增加;复合材料凝固过程中,首先析出初生Mg_2Si,之后形成Mg＋Mg_2Si共晶组织,共晶Mg_2Si依附初生Mg_2Si相生长而不形成汉字状Mg_2Si相;随着Si含量增加,Mg-9Al基体中Al含量逐渐增加,凝固行为也随之变化。With adding 3%~9% Si into Mg-9Al alloy,the in-situ Mg_2Si/Mg-9Al matrix composites with10%~30% Mg_2Si were fabricated successfully by induction heating.The microstructure and solidification mechanism of the composites prepared were investigated by optical microscopy（OM）,scanning electron microcopy（SEM）,X-ray energy-dispersive spectrometry（EDS）,X-ray diffraction（XRD）and differential thermal analysis（DTA）.The results indicate that the composites prepared are composed of Mg_2Si,Mg17Al12and Mg phase.The amounts of both Mg_2Si and Mg17Al12 phase are increased with the Si content increase.During cooling process,Mg＋Mg_2Si eutectic phase can be generated after the precipitation of primary Mg_2Si,and the eutectic Mg_2Si phase is grown on the primary Mg_2Si.The Al content in the Mg-9Al matrix is increased with the Si content,which affects the solidification behavior of the Mg-9Al matrix.

关 键 词：Mg-9Al基复合材料 MG2SI 凝固机理 

分 类 号：TB333[一般工业技术—材料科学与工程]