Effect of Interfacial Microstructure on Mechanical and Tribological Properties of Cu/WS 2 Self-lubricating Composites Sintered by Spark Plasma Sintering

In this study, Cu/WS 2 self-lubricating composites are fabricated by spark plasma sintering. Interfacial microstructure and its effect on mechanical and tribological properties are investigated. High sintering temperature at 850 °C promotes decomposition of WS 2 and its following interfacial reaction with Cu to form Cu 0.4 W 0.6 nanoparticles and Cu 2 S, enhancing mechanical properties as well as wear resistance of the composites. But the destruction of WS 2 leads to a high friction coefficient. On the contrary, for the composites sintered at 750 °C, a nanoscale diffusion zone forms at the Cu/WS 2 interface. WS 2 lubricant retains its lamellar structure. The composite shows excellent self-lubrication performance, with a low friction coefficient of 0.16. However, its mechanical properties are low, and the wear rate is one magnitude higher.