高密度脉冲电流对纯铝凝固晶粒组织及其过冷度的影响  

Influence of High Density Pulse Electric Current on Solidified Aluminum Structure and Undercooling Degree

作　　者：刘华泽[1] 赵志龙[1] 马连辉[1] 王保建[1] 

机构地区：[1]西北工业大学机电学院,陕西西安710072

出　　处：《铸造技术》2008年第10期1354-1358,共5页Foundry Technology

基　　金：陕西省自然科学基金(2006E143)资助项目

摘　　要：研究高密度脉冲电流作用下纯铝凝固组织的变化,考察放电能量对晶粒尺寸的影响。结果表明:随着脉冲能量的提高晶粒越来越细化,可以获得20μm左右的均匀细小的等轴晶。但当单次脉冲能量达到180J时,随能量的升高晶粒反而变粗,生成大量粗大的柱状晶。能量达到180J后,过冷度也随之减小,最大过冷度达到1.8℃,是同样凝固条件下不施加脉冲的过冷度(0.5℃)的3倍。The influence of high density pulse electric current on solidified structure of aluminum was studied, and the effect of different discharge energy on grain size of aluminum was investigated. The results show that solidified structure of aluminum can be refined apparently by high density pulse electric current. The grain size is reduced greatly with the increase of discharging energy, and fine equiaxed grain of 20 μm can be achieved; However, the grain size is increased with the increase of discharging energy if the single pulse energy achieves 180 J, and a large number of columnar grains is appeared. The super-cooling degree is reduced when the energy achieved 180 J, The largest undercooling degree can reach up to 1.8℃, which is 3 times bigger than that without pulse electric current.

关 键 词：高密度脉冲电流 纯铝 放电能量 晶粒细化 过冷度 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG113[金属学及工艺—金属材料]