Microstructure, mechanical and tribological properties of TiCN nanocomposite films deposited by DC magnetron sputtering

TiCN nanocomposite films are prepared by direct current magnetron sputtering from TiC combined target under different nitrogen flow rates. The composition, morphology and microstructure of the nanocomposite films are characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. Hardness and tribological properties are tested by nanoindentation measurement and ball-on-disk tribometer, respectively. With the increase of nitrogen flow ranging from 0 to 30 sccm at a work pressure of 0.3 Pa, both crystallinity and sp2 carbon content in the TiCN films increase. In addition, the ratio of TiN to Ti(C, N) increases as the nitrogen flow rate increases. The friction coefficient and wear rate could be greatly reduced due to the increase of sp2 carbon and better toughness in the composite films. TiCN nanocomposite film with high hardness and good wear resistance is obtained under a nitrogen flow rate of 30 sccm.