Influence of Ag content on microstructure, mechanical and tribological properties of WNbN-Ag composite films.

Abstract

A series of TaVN–Ag nanocomposite films were deposited using a radio-frequency magnetron sputtering system. The microstructure, mechanical properties, and tribological performance of the films were investigated. The results showed that TaVN–Ag films were composed of face-centered cubic (fcc) TaVN and fcc-Ag. With increasing Ag content, the hardness of TaVN–Ag composite films first increased and then decreased rapidly. The maximum hardness value was 31.4 GPa. At room temperature, the coefficient of friction (COF) of TaVN–Ag films decreased from 0.76 to 0.60 with increasing Ag content from 0 to 7.93at%. For the TaVN–Ag films with 7.93at% Ag, COF first increased and then decreased rapidly from 0.60 at 25°C to 0.35 at 600°C, whereas the wear rate of the film increased continuously from 3.91 × 10−7 to 19.1 × 10−7 mm3/(N·mm). The COF of the TaVN–Ag film with 7.93at% Ag was lower than that of the TaVN film, and their wear rates showed opposite trends with increasing temperature.