【摘要】 采用自制的高频脉冲电流凝固细晶处理装置,研究了不同脉冲电流参数作用下铝合金凝固组织的变化,并初步探讨了脉冲电流的作用机理。结果表明,脉冲电流峰值相同时,随着处理时间的增加,晶粒细化的程度相应增加,二次枝晶的生长会随着脉冲电流处理时间的延长受到抑制;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,逐渐被打碎,变短。因此在凝固过程中施加高频脉冲电流对铝合金的凝固组织具有良好的细化作用。更多还原

【Abstract】 Using self-regulating high frequency pulse generator, the changes of the solidification structure of Al alloys treated by different pulse current parameters were studied, and the action mechanism of pulse current was investigated. The results show that, with the increase of pulse current treating time, the extent of grain refinement grows and the growth of secondary dendrite is restrained when the pulse current is the same; with the increase of pulse current, the secondary dendrite is broken and shorter as eutectic microstructure growing between dendrite structures when the treating time of pulse current is the same, and the size of secondary dendrite reduces. So the solidification structure of Al-alloy can be well refined under high frequency pulse current during solidification.更多还原