摘要：为认识丝电爆制备纳米粉过程中大颗粒的形成特征,利用石英探针直接收集金属丝各个部分形成的粉末并进行显微分析。结果表明,丝端部形成的粉末中微米级大颗粒比例要比丝中间部分粉末中的比例大;随着初始电压的升高,丝端部与丝中间部分的粉末中微米级大颗粒比例都减小,并最终达到一致。气体放电式丝电爆过程中,丝中间部分主要通过焦耳加热的作用沉积能量;而丝端部还会受到等离子体中高温粒子的高速撞击作用,也会向丝端部沉积一部分能量。

关键词：丝电爆；纳米粉体；气体放电；等离子体；能量密度

Abstract：To understand the mechanism of the micron-size particles formation in the process of nano-powders produced by the wire electrical explosion,the powders were collected by a quartz probe,and the characters of micron-size particles were analyzed.The results show that the micron-size particles proportion of the wire ends powders is higher than that of wire center section powders.With the increasing of initial charging voltage,the micron-size particles proportion of the wire every sections powders decreases,and finally reaches unanimity.During the process of the wire electrical explosion,the energy deposits into the wire mainly by the Joule heating at the wire center section.The charged particles which come from the plasma strike on the wire surface at a high speed.Some energy also can be injected into the wire end by this effect besides of the Joule heating.

Keywords：wire electrical explosion；nano-powders；gas discharge；plasma；energy density