Structures and tribological properties of diamond-like carbon films prepared by plasma-based ion implantation on Si

DLC films ranging from 5 to 180 nm in thickness have been prepared by plasma-based ion implantation (PBII) with C on Si. The structures of the films were studied with XPS and Raman spectroscopy. The nanohardness and the intrinsic stress of the films were measured. Dry sliding wear experiments have been carried out, using a ball-on-disc tester, to investigate the tribological properties of DLC films against alumina balls, employing various normal applied loads and reciprocating frequencies. For comparison, DLC films prepared by plasma-assisted chemical vapor deposition (PACVD) on Si were also investigated. The results show that the films prepared by PBII exhibit more significant improvement in tribological properties than the films prepared by PACVD because the former present higher sp3/sp2 ratio, higher hardness and lower stress than the latter. The effects of the film thickness, the applied loads and the reciprocating frequencies on the tribological properties are also presented.