高频脉冲电流作用下铝合金的凝固组织细化

Refinement of Al-alloy Solidification Structure under High Frequency Pulse Current

采用自制的高频脉冲电流诱导凝固细晶装置,研究了脉冲电流对铝合金凝固组织的影响。结果表明,脉冲电流峰值相同时,随着处理时间的增加,晶粒逐渐细化。其中二次枝晶的生长经过断裂、脱落而得到细化。脉冲电流处理时间相同时,随着电流峰值的增加,共晶组织在枝晶间生长,二次枝晶尺寸减小,并逐渐被打碎,变短,直至最后消失。

The effect of pulse current on Al-alloy solidification structure was investigated using the self-regulating high frequency pulse generator. The results show that when the pulse current peaks are same, the Al alloy grains are refined with the increase of the pulse current time. And the growth of secondary dendrite is broken, dropped and thus refined. When the pulse current is equal, the eutectic microstructure are grown between dendrite structures with the increase of the current peak. The size of secondary dendrite decreases, and it is broken, shorter and disappeared at last.