氩气中铝金属丝电爆炸放电电流波形的研究

Study on the Discharge Current Waveform of Aluminum Wire Electrical Explosion in Argon

金属丝电爆炸放电波形研究是分析负载能量耦合效率等特性的基础。为此,采用步进电机驱动金属丝端部向高压平板电极运动,通过高压电场击穿环境气体,将大电流导入金属丝中,完成电爆炸。基于该实验方案,提出了一种金属丝电极向高压电极运动过程中、环境气体击穿时,两电极间气隙长度的计算方法。并利用电路模型对氩气中铝电爆炸丝放电电流进行了数值模拟,最后分析了不同实验因素(充电电压、金属丝直径及充气压力)对放电电流波形的影响。结果表明:将计算得到的气隙长度代入电路模型,模拟得到的金属丝放电电流波形与实验测量结果基本相符;当充电电压由20 k V提高到28 k V时,放电电流峰值、上升速度分别增大了约6 k A、10 k A/μs,金属蒸汽击穿时刻提前了近0.4μs;当氩气气压从0.10 MPa提升到0.20 MPa时,金属蒸汽击穿时刻由1.5μs推迟到2.1μs。

Studying the discharge current waveform of wire electrical explosion is crucial to further analyzing the load characteristics including energy coupling efficiency. To this end, we drove the wire to approach the high voltage plate electrode using stepping motor. When ambient gas was broken down by electric field, discharge current was introduced to the wire, followed by the occurrence of wire explosion. In addition, based on the experimental scheme, a calculation me- thod was proposed to determine the gas-gap length between two electrodes at the point of ambient gas breakdown during the motion of wire electrode. Also, discharge currents of the aluminum wire electrical explosion in argon were achieved by simulating the circuit model with the gap length obtained above. Finally, how the discharge currents were influenced by different experimental parameters （such as the charged voltage, the length of the wire, as well as the gas pressure） was analyzed. The results showed that the discharge currents calculated by our method agreed well with the experimental data by substituting the calculated gap length into the circuit model. As the charging voltages were improved from 20 kV to 28 kV, the peak value and the rise of rate for discharge currents increased by about 6 kA and 10 kA/us, respectively. When the argon pressures increased from 0.1 MPa to 0.20 MPa, the breakdown times of metal vapor were put off from 1.5us to 2.1 ixs.