Sr细化AZ91D合金部分重熔过程的组织演变  

Microstructure Evolution of Magnesium Alloy AZ91D Refined by Sr Addition During Partial Remelting

作　　者：周全[1] 陈乐平[1] 

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《热加工工艺》2008年第23期9-12,共4页Hot Working Technology

基　　金：江西省教育厅基金资助项目(GJJ08208)

摘　　要：研究了添加微量Sr细化的AZ91D镁合金部分重熔过程中的组织演变,考察了加热温度和等温时间对合金初生相形态和尺寸的影响。结果表明:添加质量分数为0.1%的Sr,在610℃浇注的AZ91D镁合金部分重熔后,可以获得初生相为球状或粒状的非枝晶半固态合金,基本具备触变过程所需要的组织状态;等温时间一定时,随着重熔温度提高,半固态组织球化过程加快,但加热温度过高,试样表面有大量液相渗出,并在自重作用下严重变形;当重熔温度一定时,随等温时间延长,初生相变得愈加圆整,但等温时间过长,初生相有长大倾向。The non-dendritic semi-solid magnesium alloy AZ91D was prepared by reheating the AZ91D alloy refined by tiny Sr addition. The microstructure evolution of the alloy refined by Sr addition during partial remelting, and the effects of heating temperature and holding time on the partial remelted microstructure of the alloy were investigated. The experimental results show that the alloy with 0.1% Sr addition and pouring temperature 610℃ partially remelted has fine microstructure, which is basically suitable for thixoforming. The higher the heating temperature or the longer the holding time, the smoother the boundaries of primary grains. But if the remelting temperature is too high, some liquid metal is exuded from the surface of samples and the samples are deformed by their own gravity. If the holding time is too long, the primary grains prefer to become large.

关 键 词：AZ91D镁合金 SR 半固态合金 部分重熔 

分 类 号：TG146[一般工业技术—材料科学与工程]