Dependance of Wear of Cu-Cr-S Alloy on Hardness and Electrical Conductivity in Sliding Electrical Contact

Abstract

Wear of material in unlubricated sliding type electrical contact (e.g. contact wires for trolleys and rotor materials in electric engines and current generators) is one of the main failure causing modes of copper (Cu)-based alloys. High electrical conductivity, high tensile strength, suitable hardness and wear resistance under such conditions should be provided. In a present paper required properties of dispersion-hardened Cu-based electrical conductive alloy (Cu-0.68 wt. % Cr-0.02 wt. % S) were obtained by equal-channel angular press treatment with following six press treatments by B_c route and suitable heat treatment. The wear tests were carried out in unlubricated sliding pair with graphite disk. Optimal properties were reached after annealing at 450 °C for 1 h, exhibiting a lowest wear rate (~1.9268·10^-9 g·m^-1), high electrical conductivity (up to 95 % IACS) and Vickers microhardness up to 1.7 GPa, respectively.