Effects of electromagnetic field on structure and heat treatment behavior of Mg-Li-Al alloys  

作　　者：马蕾娟 郝海 董汉伟 张兴国 金俊泽 

机构地区：[1]School of Materials Science and Engineering,Dalian University of Technology

出　　处：《中国有色金属学会会刊：英文版》2008年第A01期96-100,共5页Transactions of Nonferrous Metals Society of China

基　　金：Project(107031)supported by the Key Grant of Science & Technology of the Ministry of Education of China

摘　　要：The effects of external fields such as electromagnetic field on the structure and heat treatment behavior of Mg-Li-Al alloys were studied.Mg-8Li-3Al alloys cast with and without electromagnetic stirring were used for solution treatment and aging treatment. Experimental results show that the dendritic arms are broken and a large quantity of equiaxed grains appear in the microstructure of specimens with electromagnetic stirring(EMS).With the increase of the quenching temperature(150-350℃),the solution of Mg and Al in solidβphase increases,and the Brinell hardness of the alloy increases as well.Aging peak and over aging happen becauseθ(MgLi_2Al) which precipitates in theβmatrix and strengthens the alloy is unstable and transforms to stable AlLi phase.Aging curves of EMS specimens change in a smaller amplitude.The effects of external fields such as electromagnetic field on the structure and heat treatment behavior of Mg-Li-Al alloys were studied. Mg-8Li-3Al alloys cast with and without electromagnetic stirring were used for solution treatment and aging treatment. Experimental results show that the dendritic arms are broken and a large quantity of equiaxed grains appear in the microstructure of specimens with electromagnetic stirring （EMS）. With the increase of the quenching temperature（150-350℃）, the solution of Mg and Al in solid β phase increases, and the Brinell hardness of the alloy increases as well. Aging peak and over aging happen because θ（MgLi2Al） which precipitates in the fl matrix and strengthens the alloy is unstable and transforms to stable AlLi phase. Aging curves of EMS specimens change in a smaller amplitude.

关 键 词：MG-LI-AL合金 热处理 磁搅拌 焊接 温度梯度 

分 类 号：TG146.22[一般工业技术—材料科学与工程]