(上海交通大學(xué) 材料科學(xué)與工程學(xué)院，上海 200030)
摘 要: 研究了高密度脈沖電流對A356鋁合金凝固組織的影響，實驗中對液相線以下熔體的凝固過程在不同階段進行電脈沖處理。對比實驗結(jié)果表明：經(jīng)過電脈沖處理后，A356的合金凝固組織得到明顯細化； 在同樣的電脈沖條件下，凝固組織細化效果與電脈沖放電開始時間有關(guān)，凝固過程中放電開始時間越早，凝固組織細化效果越明顯；反之，凝固組織細化效果較差；同時，脈沖充電電壓越高，凝固組織細化程度越大。定量計算了脈沖電流產(chǎn)生的電磁力并分析了脈沖電流影響凝固組織的作用機制。
關(guān)鍵字: A356鋁合金；凝固組織；脈沖電流；細化
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
