含气隙的铝丝电爆炸特性

Electric Explosion Characteristics of Air-gap Aluminum Wire

在金属丝电爆炸法批量制备纳米颗粒的工业生产中,金属丝在连续送丝工作模式时与高压电极间存在气隙,为此基于实验和数值模拟研究了气隙对铝丝电爆炸特性的影响。在常压空气介质条件下,由送丝装置往高压电极板输送直径0.4mm的铝丝进行电爆炸实验,采用高速相机对整个送丝过程进行光学诊断,获取了不同电压下的气隙击穿长度,并建立比作用量模型和Rompe-Weizel的火花电阻模型对考虑气隙的电爆炸波形进行了电路模拟。研究结果表明气隙击穿长度与充电电压之间呈现正比关系,其比例约为20 kV/cm,空气间隙对电爆炸的影响较小,增加充电电压可有效提高能量沉积速率加快相变过程。连续送丝时,气隙击穿长度会随着爆炸次数增加而减小。

In the industrial production of nanoparticles by the metal wire electric explosion method, different voltages will have different air gap breakdown lengths in the case of continuous wire feeding. Consequently, in order to study the influences of voltage and air gap length on the electrical explosion characteristics of aluminum wire, a wire feeder was used to transport metal wires with a diameter of 0.4 mm to the high-voltage electrode plates under the condition of 1 atmosphere of air. A high-speed camera was used to perform an optical diagnosis in the wire feeding process, and the air gap breakdown length under different voltages was obtained. Then, the specific action model and Rompe-Weizel’s spark resistance model were used to simulate the experiment. The above research shows that there is a proportional relationship between the breakdown length of the air gap and the charging voltage, and the ratio is about 20 kV/cm. Under continuous wire feeding conditions, the air gap breakdown length will decrease as the number of explosions increases. The air gap has a negligible effect on the electric explosion. Increasing the charging voltage can effectively increase the energy deposition rate and accelerate the phase change process.