Investigation on arc erosion behaviors and mechanism of W70Cu30 electrical contact materials adding graphene

Abstract

In this work, graphene was chosen to add into W70Cu30 alloys to develop properties of arc erosion. The effect of graphene addition on arc ablation behavior of W70Cu30 contacts was investigated by the measurement of weight-loss and the vacuum electrical breakdown tests. Also, the surface morphology of W70Cu30 contacts was analyzed by using scanning electron microscopy (SEM) after arc breakdown the first and 100 times. The results reveal that addition of graphene can enhance the breakdown strength a lot, which reach up to ∼45.5%, with a maximum value of 8.5 × 106 V/m. Compared with W70Cu30 alloys without any additives, the surface morphology of W70Cu30 alloys with graphene addition have a slight splash of molten copper and a small, flat cathode craters, thus, avoiding the concentration erosion on the surface of contacts. The main ablation mechanisms of W70Cu30 alloys with graphene addition was considered to be electron transition, energy consumption and difference work function of W, Cu, graphene, respectively.