Liquid Phase Formation on Graphite Electrode Surface in Arc Discharge

Abstract

The graphite electrode surface is studied after impact by an electric arc burning in an argon atmosphere at a pressure of 50 kPa. The arc occurred as a result of the local destruction of a graphite rod heated by electric current and preliminarily kept for 2 × 10³ s at a temperature of about 3 kK. After the arc discharge with a current of about 100 A with a duration within 1 s, we found drop-like particles, 0.1–0.3 mm in size, on the graphite electrode surface, which is evidence of the local occurrence of liquid carbon phase at a temperature of about 3.3 kK. With longer arc burning, the melting zone propagated over the entire working surface of the electrodes; the surface became smoothed.