Sliding wear behavior of copper alloy contact wire against copper-based strip for high-speed electrified railways

This paper reports the study of the sliding wear behavior of the Cu-Ag-Cr wire. Cu-Ag-Cr alloy is a promising contact wire material for high-speed electrified railways, which has an excellent combination of mechanical strength and electrical conductivity. Wear tests were conducted under laboratory with a special sliding wear apparatus, which simulated the tribological conditions of sliding current collectors on overhead wires in the railway system. The Cu-Ag-Cr alloy wire was slid against a copper-based powder metallurgy strip under unlubricated conditions. The same strip as those in the train systems were used. Worn surfaces of the Cu-Ag-Cr alloy wire were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDS). Within the studied range of electrical current, normal pressure and sliding speed, the wear rate increased with the increasing electrical current and the sliding distance. Compared with a Cu-Ag contact wire under the same conditions, the Cu-Ag-Cr alloy wire had much better wear resistance. Adhesive wear, abrasive wear and arc erosion were the dominant mechanisms during the electrical sliding processes.