Experimental Study on Friction and Wear Behaviors of Carbon Rubbing against Copper Material under Electric Current

An experimental study on friction and wear properties of carbon strip rubbing against copper contact wire was carried out on a pin-on-disc frictional tester under electric current. The result indicates that the coefficient of friction slowly increases with increasing of electric current. The value of friction coefficient is low, generally not more than 0.125. The wear volume of pin specimen increases with increasing of electric current. The wear volume of pin specimen is very low, generally not more than 0.075g. Through observing the SEM morphology of worn specimens, it can be found that there are obvious pits of arc ablation and traces of melting metal on worn surface. Worn surfaces of the worn specimens are analyzed by an energy dispersive X-ray spectroscopy. It can be observed that the oxidation wear occurs in the frictional process due to arc erosion and significant temperature rise. Therefore the arc erosion and oxidation wear are a main wear mechanism accompanied by materials transferring in the process of electrical sliding friction.