On the control of deposition process for enhanced mechanical properties of nc-TiC/a-C:H coatings with DC magnetron sputtering at low or high ion flux

Nanocomposite coatings consisting of nanocrystallites embedded in an amorphous matrix can be tailored to exhibit unusual combination of properties such as high hardness and modulus combined with low friction and wear. The properties of the coatings are governed by parameters of the deposition plasma, which are a nontrivial function of the deposition process parameters. Energy flux onto the growing films provided by ionized species is one of the key parameters influencing the properties of coatings. This study is focused on the influence of ion flux on the properties of the growing nc-TiC/a-C:H thin film in order to achieve enhanced mechanical properties. Two different magnetic field configurations were used. The saturated ion current on the substrate was found to be seven times higher in the strongly unbalanced magnetic configuration as compared to well-balanced configuration. The deposition temperature was constant at ~ 320 °C, which is higher than the usual temperature for similar depositions of nc-TiC/a-C(:H) coatings. The structure and mechanical properties of the coatings prepared at low or high ion flux were studied and compared. It is concluded that the level of the impinging ion flux in DC magnetron sputtering is not a significant factor influencing the mechanical properties of the coatings in the presented setup.