Arc erosion behavior and mechanism of Cu/Ti3SiC2 composites in air and c-C4F8/N2 mixture after multiple arc discharges

Abstract

The arc erosion behavior of Cu/Ti3SiC2 composites in air and c-C4F8/N2 (75/25) mixture was investigated after arc discharges of 1, 100, and 200 cycles. Arc erosion parameters such as breakdown strength, arc duration and breakdown current were recorded. Whether in air or C-N-75-25, the value of the breakdown strength fluctuated with an increase in the number of operations owing to the change in the height of the highest protrusion point, and the breakdown strength remains basically stable after each arc discharge. The arc energy in the C-N-75-25 mixture is lower than that in air. After multiple arc discharges, the erosion pits were scattered over the entire surface within a large area in air. In c-C4F8/N2 (75/25) mixture, although the material surface appeared black owing to carbon deposition, only one crater-like pit was found. In both air and c-C4F8/N2 (75/25) mixture, only a small number of cracks were observed after multiple arc discharges owing to the self-healing effect of the molten Cu liquid flowing into the cracks and condensation. After multiple arc discharges, variations in the ability of the experimental atmosphere to capture electrons resulted in differences in breakdown strength and erosion area. Surface roughness affects breakdown strength but does not play a decisive role. The addition of Ti3SiC2 enhanced the viscosity of the molten pool and increased the work function of the material.