高密度脉冲电流对纯铝凝固组织的影响及其内在机理研究  

Influence of High Density Pulse Electric Current on Solidified Structure of Aluminum and Analysis of Internality Theoretics

作　　者：王保建[1] 赵志龙[1] 徐义库[2] 刘林[2] 

机构地区：[1]西北工业大学机电学院,陕西西安710072 [2]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《热加工工艺》2008年第3期1-4,8,共5页Hot Working Technology

基　　金：陕西省自然科学基金资助项目(2006E143)

摘　　要：研究了高密度脉冲电流作用下纯铝凝固组织的变化,考察了不同放电电压和放电电容对纯铝晶粒尺寸的影响。从高能量密度脉冲电流对纯铝结晶的形核率、过冷度和热效应三个方面的影响,对高能量密度脉冲电流细化晶粒的机理做了深入分析。结果表明:高密度脉冲电流可以显著地细化纯铝的凝固组织。随着放电能量的提高,纯铝的晶粒尺寸有大幅度的减小,可以获得均匀细小的等轴晶;但是当放电能量达到270J后,晶粒随放电能量的升高反而变粗,生成大量的粗大的柱状晶。The influence of high density pulse electric current on solidified structure of aluminum was studied, and the effect of different voltage and different capacitance on grain size of aluminum was investigated. From the influence of high density pulse electric current on nucleation ratio, super-cooling degree and thermal effect of aluminum crystal, the theoretic analysis on grain refinement by high density pulse electric current were made. The results show that solidified structure of aluminum can be refined apparently by high density pulse electric current. The grain size reduces greatly with the increase of discharging energy, and fine equiaxed grain can be achieved; but after the discharging energy achieves 270 J, the grain size increases with the increase of discharging energy, and lots of bulky columnar grains appears.

关 键 词：高密度脉冲电流 凝固组织 晶粒细化 过冷度 热效应 

分 类 号：TG244.3[金属学及工艺—铸造]