Study on the Electrical Friction Wear Properties of Ag-G-La2O3-WS2 Composites

With the increase of current density and operating speed, the performance of Ag-G electrical contact materials cannot meet the needs of the rapid development of modern industry. In this study, lanthanum oxide (La₂O₃) and tungsten disulfide (WS₂) were added to silver-graphite (Ag-G) materials to improve the electrical wear properties of electrical contact materials. Ag-G-La₂O₃-WS₂ composites were prepared by powder metallurgy method, and electrical sliding experiments were carried out using a ring-block wear experimental device. The results showed that the electrical friction coefficient of Ag-G-La₂O₃-WS₂ composites gradually increased from 0.105 to 0.143 with the increase of the La₂O₃ content, the electrical wear rate gradually decreased from 2.453 × 10⁻⁷ mm³/(N·m) to 1.064 × 10⁻⁷ mm³/(N·m) and subsequently increased to 1.835 × 10⁻⁷ mm³/(N·m), the contact voltage drop gradually decreased from 0.283 to 0.249 V and subsequently increased to 0.306 V. When the volume ratio of Ag-G-La₂O₃-WS₂ is 75:15:4:6, it shows better performance. The main wear forms of Ag-G-La₂O₃-WS₂ composites are adhesive wear and abrasive wear. In the electric friction wear experiment, WS₂ was partially oxidized to WO₃, while the rest of the composition remained unchanged. The lubrication film changes the contact between the specimen and the slip ring from metal–metal to metal–lubrication film–metal, which reduces the wear of the material, and the lubrication film has a great influence on the wear performance of the material.

Graphical Abstract