Enhancing the tribological performance of Cu-WS2 composites with Ag-shell/Cu-core structure

The interface reaction between Cu and WS2 is an essential factor affecting the tribological properties of Cu-WS2 composites, and it is urgent to avoid and reduce the interface reaction. In this study, Ag-shell/Cu-core powder was fabricated by electroless plating, which was used to produce the (Ag shell/Cu core)-WS2 composites. For comparison, Cu-WS2 composites were prepared with pure Cu powder. The microstructure and tribological behaviors of (Ag shell/Cu core)-WS2 and Cu-WS2 composites were carefully investigated. Results revealed that the friction coefficient and wear rate of (Ag shell/Cu core)-WS2 were 0.21 and 15.4 x 10-6 mm3/(N center dot m) under 5 N, which were 66% and 79% lower than those of Cu-WS2 composites, respectively. The superior tribological performance of (Ag shell/Cu core)-WS2 composites stemmed from Ag-shell/Cu-core structure, which prevented the interfacial reaction during hot-pressing (HP) sintering. The WS2 could be well retained and form a low-shear transfer film with a coverage of more than 86.5%.