大脉冲电流下钨铜电极水和空气中的烧蚀特性

针对水中、空气中脉冲放电条件下金属电极烧蚀速率及烧蚀机理差异,对脉冲大电流作用下水中、空气中钨铜电极的烧蚀特性进行了对比研究。在保证放电电流波形一致性的前提下,通过采用高精度天平测量并获取了水中、空气中钨铜电极的阴、阳极烧蚀速率及总烧蚀速率,并对电极表面进行了二次电子观察和背散射电子观察分析。结果表明,大脉冲电流作用下,水中钨铜电极烧蚀较空气中更为严重,钨铜电极的烧蚀主要是金属蒸发引起的汽相侵蚀。由于水介质较空气具有不可压缩性,水中放电电弧集中,电极表面电弧斑点处电流密度和电流作用时间较空气中更为严重,同时由于水中脉冲放电时发生的高温物理化学反应,是造成水中电极烧蚀要高于空气中的根本原因。

Tungsten copper electrode erosion characteristics under high pulse current in water and air

According to the difference between electrode erosion rate and erosion mechanism of pulse discharge in water and that in air, a comparative study of tungsten copper electrode erosion characteristics was carried out under high pulse current. Under the uniform waveform of discharge current, using a high precision balance, the cathode erosion rate, anode erosion rate and total erosion rate of tungsten copper electrode were obtained, and the electrode surface was analyzed by ETD and SSD. The results show that the tungsten copper electrode erosion is more serious in water than in air under high pulse current, the erosion of the tungsten copper electrode is mainly caused by the evaporation of metal. Because the incompressibility of water is higher than air, pulse arc discharge in water is more focused, the current density is higher and the current duration time is longer in water than that in air of arc spot, the high temperature physical and electrochemistry reaction caused by pulse discharge in water, is the main cause which leads electrode erosion more serious in water than in air.