高密度脉冲电流对过共晶Al-Si合金凝固组织的影响  

Effect of high density pulse current on solidification structure of hypereutectic Al-19Si alloy

作　　者：何树先[1] 王俊[1] 孙宝德[1] 周尧和[1] 

机构地区：[1]上海交通大学材料科学与工程学院,上海200030

出　　处：《中国有色金属学报》2002年第2期275-278,共4页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展规划资助项目 (G19990 64 90 0 -4 ) ;美国GM (中国 )公司基金资助项目

摘　　要：研究了高密度脉冲电流对过共晶Al 19Si合金凝固组织的影响。结果表明 :未经任何处理的试样凝固组织中含有大量的长杆状初生Si,其长宽比较大 ,且共晶Si尺寸较大 ;而经过高密度脉冲电流处理后 ,凝固组织中初生Si转变为块状 ,长宽比显著减小 ,共晶Si呈短杆状 ,尺寸较小 ,另外在试样的局部存在初生Si晶粒破碎现象 。The influence of high density pulse electric current(HDPEC) on the solidification structure of hypereutectic Al 19Si alloy was studied. The results show that there exist lots of primary Si phases with long pole shape in the solidification structure when the specimen are not treated by HDPEC, and the aspect ratio of Si grain is larger. The size of eutectic Si is large. However, through HOPEC, the morphology of the primary Si phases changes into blocky structure greatly, and the aspect ratio of Si grain becomes smaller. The eutectic Si phases appear short pole, and the size of them decreases obviously. Moreover, there exist some smallest and broken Si grains in certain area of the specimen, which is resulted from the non equilibrium distribution of the electric magnetic force existed in the melt.

关 键 词：凝固组织 高密度脉冲电流处理 电磁力 过共晶铝硅合金 晶粒细化 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG166.3[金属学及工艺—金属材料]