(上海交通大学 材料科学与工程学院，上海 200030)
摘 要: 研究了高密度脉冲电流对A356铝合金凝固组织的影响，实验中对液相线以下熔体的凝固过程在不同阶段进行电脉冲处理。对比实验结果表明：经过电脉冲处理后，A356的合金凝固组织得到明显细化； 在同样的电脉冲条件下，凝固组织细化效果与电脉冲放电开始时间有关，凝固过程中放电开始时间越早，凝固组织细化效果越明显；反之，凝固组织细化效果较差；同时，脉冲充电电压越高，凝固组织细化程度越大。定量计算了脉冲电流产生的电磁力并分析了脉冲电流影响凝固组织的作用机制。
关键词: A356铝合金；凝固组织；脉冲电流；细化
current on solidification structure
of A356 alloy
（School of Materials Science and Engineering,
Shanghai Jiaotong University, Shanghai 200030, China）
Abstract:The effect of high density pulse electric current (HDPEC) on the solidification structure of A356 alloy was investigated. In the experiments, the HDPEC was discharged at different stage of the solidification of A356 alloy. The control results showed that the solidification structure of A356 alloy was refined apparently when the HDPEC was discharged during the solidification. And the micro structure refinement is related to the beginning time of the HDPEC discharge, the earlier the discharge during the solidification, the better the refinement. Meanwhile, the higher HDPEC discharge is beneficial to modification of solidification structure. The mechanism of HDPEC discharge was analyzed quantitatively.
Key words: A356 alloy；solidification structure；electricpulse current；refinement
