The surface microstructure of CuCr and CuCrWC contact alloys af-ter conditioning is investigated. Experimental results show that the conditioning process produces a small melt layer on the surface which has much fine microstruc-ture and more uniform microcompositions
then its dielectric strength increases. The addition of WC in CuCr alloy can increase its dielectric strength. The effect of current on conditioning process is also discussed in this paper.