Tribological performance of graphite-like carbon films with varied thickness

Graphite-like carbon (GLC) films with different thickness were deposited on 316 L stainless steel using closed field unbalanced magnetron sputtering system to investigate the influence of film thickness on the microstructure, mechanical and tribological properties. The results showed that the surface of the deposited films exhibited granular-like morphology, and the sp2 content, surface roughness increase with the increase of film thickness, leading to the lower of hardness and higher of the internal stress. Both of the friction curves obtained by nano-tribological tests and fretting wear experiments revealed a three-stage evolution tendency with the same wear mechanism for the first two stages. The intermediate thick GLC film had the lowest specific wear rate, whilst the fretting fatigue life increased with film thickness.