Characterization of Diamond-Like Carbon and Carbon Nitride Films Symthesized by Hollow Cathode Discharge Method

Diamond-like carbon (DLC) and carbon nitride (C-N) films have the superior properties of hardness and wear-resistance. They have been investigated extensively for several applications. In this present study, DLC and C-N films were prepared on silicon wafers, stainless steel sheets, high speed steel blocks and WC-Co tips by the hollow cathode discharge method at the high deposition rate of 0.3μm/min. Silicon or tungsten carbide-cobalt was deposited as an interlayer in order to improve the adhesion of DLC and C-N films. Raman spectra of the DLC and C-N films showed distinct D and G bands. The indenting hardness of the C-N films was found to be larger than that of the DLC films. The intensity ratio of the D band to G band in the DLC films related linearly to the indenting hardnesses. On the other hand, the intensity ratios in the C-N films were almost constant in spite of the different conditions of deposition. The indenting hardness in the C-N films depended on the amount of contained nitrogen. The DLC films exhibited a lower friction coefficient compared with the C-N films.