Shuguo Jia

Electrotribological behavior of Cu−Ag−Zr contact wire against copper-base strip

Cu−Ag−Zr alloy has an excellent combination of mechanical strength and electrical conductivity, and is a promising contact wire material for high-speed electrified railways. An investigation of the electritrobological behavior of Cu−Ag−Zr wire is presented here. Wear tests are conducted under laboratory conditions with a specified sliding wear tester that simulated train motion under an electrical current applied across the sliding interface. The Cu−Ag−Zr alloy wire is slid against a copper-based powder metallurgy strip used in railway systems under unlubricated conditions. Worn surfaces of the Cu−Ag−Zr alloy wire are 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 increases with increasing electrical current and sliding distance. Adhesive wear, abrasive wear, and electrical erosion are the dominant mechanisms during the electrical sliding processes. Compared with a Cu−Ag contact wire under the same test conditions, the Cu−Ag−Zr alloy wire has much better wear resistance.

Electrotribological property of the Cu−Ag−Cr alloy with high-strength and high-conductivity

By means of a vacuum induction furnace, a Cu−Ag−Cr alloy was produced. The electrotribological property and mechanism of the Cu−Ag−Cr alloy wear studied via wear property tests, scanning electron microscope (SEM), energy dispersive X-ray spectrum (EDS) and transmission electron microscopy (TEM). Wear tests were conducted with a specially designed sliding wear tester, which simulated the tribological conditions of sliding current collectors on contact wires in a railway system. The alloy wire was slid against a copperbased powder metallurgy strip under non-lubricated conditions. The results showed that the wear rate of Cu−Ag−Cr alloy increases as the sliding speed increases under a normal load. Adhesive wear, abrasive wear, and electrical erosion wear are the governing wear mechanisms under the electrical current sliding processes. Under the same conditions, the wear resistance of the Cu−Ag−Cr alloy is 2–3 times that of the Cu−Ag alloy.