Dynamic variation of arc discharge during current-carrying sliding and its effect on directional erosion

Current-carrying sliding tests of sintered Cu/Graphite composite were conducted at 80A and 20m/s. The dynamic variation of arc discharge captured by a high speed camera revealed a migrating behavior of arc discharges along the sliding direction, and this, in turn, caused an aggravated erosion of worn surface, as consistently proved by SEM, EDS and 3D characterizations. Based on the erosion mechanism, arc discharge induced material erosion could be alleviated by various means, including inhibiting migration of arcs by proper surface modification and employing functionally gradient materials (from mechanical wear resistant to arc discharge erosion resistant) in current-carrying sliding conditions. •Dynamic variation of arc discharge under sliding condition is examined.•An aggravated erosion of materials along sliding direction is reported.•The mechanism for directional erosion is explored.