Tribological Characteristics of TiN and TiCN Hard Coatings Prepared by Pulsed D.C. Plasma Enhanced C

The tribological characteristics of TiN and TiCN hard coatings prepared by pulsed d.c. plasma enhanced chemical vapour deposition were investigated using a pinondisk friction and wear tester. The crosssection morphology of the films was observed with a scanning electron microscope, while the phase composition of the films determined on an Xray diffractometer. Moreover, the micro hardness of the films was measured on a microhardness tester, while the bonding strength of the film to the substrate determined with an indentation tester and a scratch tester, respectively. The results showed that the ratio of CH4 in the mixed gas had great effect on the composition, structure, and tribological behavior of the corresponding TiCN films. TiCN film had higher hardness and better wearresistance than TiN film. It registered lower friction coefficients and higher interfacial bonding strength than the TiN film as well. This was attributed to the inclusion of C in the film, which led to the formation of TiC and improved the interfacial bonding of the film.