Arc Erosion Behavior of Cu/Ti3SiC2 Cathodes in c-C4F8 Gas as a Substitute for SF6 Gas

In this paper, the arc erosion behavior of copper/titanium silicon carbide (Cu/Ti3SiC2) cathodes in air, sulfur hexafluoride (SF6) and octafluoroisobutane (c-C4F8) were investigated at 7.5 kV, and the possibility of c-C4F8 gas as a substitute for SF6 gas was assessed. The material was oxidized in air with large cracks, while it maintained a good structure in SF6 and c-C4F8, although there were some bulges in the erosion center. Fluorinated carbon (CFx) was detected in c-C4F8, which improved the arc erosion resistance. The arc extinguishing performance of different gases was analyzed by establishing the Mayr arc model and calculating the time constant theta and power loss coefficient N-0. The results indicate that the time constant. decreases in the order air > c-C4F8 >SF6, while the power loss coefficient N-0 decreases in the order c-C4F8 > SF6 > air. An arc erosion mechanism was also proposed in this study.