Al-TiC对AZ91合金铸态组织的影响  

Effect of Al-TiC Master Alloy on As-cast Microstructure of AZ91 Magnesium Alloy

作　　者：韩辉[1] 刘生发[1] 康柳根[1] 刘林艳[1] 

机构地区：[1]武汉理工大学材料科学与工程学院,武汉430070

出　　处：《武汉理工大学学报》2007年第5期1-4,共4页Journal of Wuhan University of Technology

基　　金：湖北省自然科学基金(2004ABA110);武汉理工大学科学基金(XJJ2005021)

摘　　要：利用EPMA、SEM和XRD等测试手段研究了铸造反应法制备的Al-10%TiC(质量分数,下同)中间合金对AZ91合金晶粒的细化作用。结果表明:晶粒尺寸随中间合金加入量的增加而减小,当加入量为0.5%时,-αMg晶粒的尺寸由基体合金的107μm降至48μm,降低幅度约为55%,而且β相由连续网状向断网状或粒状转变,弥散程度增加。α-Mg晶粒的细化机制可能为:原位TiCp可作为初生-αMg的异质晶核。此外,悬浮在熔体中的TiCp在结晶过程中被推移到固/液界面前沿的液相中,从而降低了初生-αMg相的生长速度,最终导致α晶粒的进一步细化。The refining effect of Al-10%TiC master alloy （processed via Casting Contact Reaction Method） on as-cast microstructure of AZ91 alloy was investigated by means of EPMA, SEM and XRD and so on. The results showed that the size of grains decreased with the increasing of adding amount of master alloy, which was reduced from 107μm（matrix alloy） to 57 μm and the reduced extent was about 55 % while adding 0.5 %TiC. In addition, the continuous net-like β-phases transformed into discontinuous net-like or granular. The refining mechanism of α-Mg maybe was the in-situ TiCp particles act as the heterogeneous nucleation of primary α-Mg. Moreover, the TiCp particles suspended in the melt were pushed onto the front of solid-liquid interface during crystallization, consequently, which reduceed the rate of growth of primary α-Mg phases and finally resulted in the further refined of a phases.

关 键 词：AZ91镁合金 Al-TiC中间合金 显微组织 

分 类 号：TG146[一般工业技术—材料科学与工程]