Characteristics of arc erosion for Cu-C composite materials in air

Arc erosion of Cu-C composites was investigated in air. The eroded zones on the cathode surface were observed by a scanning electron microscope, and the cathode erosion rates were measured. It can be found that the main mass loss results from ejection of copper and oxidization of carbon during discharges. The degree of erosion increases with the copper content. Meanwhile, the arc erosion rate is larger for the Cu-C materials with higher copper content. A large number of bubble-like particles appear on the electrode surface. The formation of those particles is closely related to the melting and ejection of copper and material transfer between the electrodes.