Comparative investigation into the friction and wear behaviours of a Cu–Ag contact wire/carbon strip and a pure copper contact wire/carbon strip at high speeds

Several experimental tests are conducted on a high-speed block-on-ring tester to study friction and wear behaviours of a Cu–Ag contact wire and a pure copper contact wire rubbing against a carbon strip with electric current. The test parameters are set as follows: electric current 0–250A, sliding speed 110–170km/h and normal load 50–130N. The friction coefficient, wear volume and arc discharge energy are analyzed. The experimental results show that the friction coefficient of the carbon strip/Cu–Ag alloy contact wire is larger than that of the carbon strip/pure copper contact wire, and that the wear rate of the carbon strip which rubbed against the Cu–Ag alloy contact wire is larger than that of the carbon strip which rubbed against the pure copper contact wire. Discussion is presented to explain the friction and wear behaviours. •The friction and wear properties of two kinds of friction pairs are studied.•Rub against Cu–Ag alloy contact wire, there is a larger friction coefficient.•Rub against Cu–Ag alloy contact wire, the carbon strip has a larger wear rate.•There is an optimal normal force, at which the wear of the contact strip is minimum.•Two main mechanisms for wear of the contact strip are presented.