The tribology behaviors of textured graphite-like carbon film under air and aqueous environments

Abstract

The pattern of micropore with various diameters (0, 0.5, 1.5 and 5 μm) on the surface of single crystal silicon was obtained through laser treatment and then the graphite-like carbon (GLC) film was deposited on these substrates through magnetron sputtering technology. The effect of micropore diameter on tribological performance of GLC film under air and aqueous environments was systematically investigated. The results indicated that the micropore diameter and test environment greatly affected the tribological behavior of GLC film. The friction coefficient (COF) and wear loss of GLC film were significantly improved in aqueous environment compared with in air. This was attributed to the formation of aqueous molecular film, which could obstruct the immediate contact between GLC film and counterpart. Meanwhile, the anti-wear ability of GLC film in aqueous environment strengthened firstly and then weakened as the micropore diameter increased. When the micropore diameter was 1.5 μm, the GLC film displayed the lowest wear rate of 0.32 × 10−8 mm3 Nm−1 in aqueous environment, which was 67.65%, 46.08% and 26.67% lower than the micropore diameters of 0, 0.5 and 5 μm, respectively. This was due to the synergistic effect of surface roughness and lubricant (graphitized particles and aqueous medium) captured by micropores.