W–C Electrode Erosion in a Pulsed Arc Submerged in Liquid

Abstract

Electrode erosion was studied in pulsed arcs ignited between two electrodes comprised of 99.99% C (graphite) and 99.5% W submerged in deionized water or analytical (99.8%) ethanol. In the both cases the erosion rate increased proportionally to the pulse energy, and the total electrode erosion per unit energy was inversely proportional to the discharge pulse duration. Fifteen and sixty-μF discharge capacitors were used for formation of the pulses in water. It was obtained that, respectively (a) erosion of the tungsten anode (Wa) was by factors of 5–6 and ∼10 greater than that of the carbon (Cc) cathode; (b) erosion of the carbon anode (Ca) was by a factor of 1.34 greater and by a factor of 2.65 less than that of the tungsten cathode (Wc); (c) the total erosion rate of both electrodes (anode and cathode) per unit pulse energy for the Wa–Cc pair was greater by factors of 11 and 12.5 than that for the Wc–Ca pair.