Oxidation behaviours of Ti(C, N, O) nanocomposite coatings

It is known that the lifetime of Ti-based hard coatings is dependent on the oxidation rate of Ti. Ti(C,N,O) coatings prepared by an unbalanced magnetron sputtering process had been shown to have improved tribological properties. The present studies applied a static oxidation approach to explain that the oxidation activation energy could be correlated to wear rate. The properties of the oxidised films were analysed by Raman spectroscopy and scanning electron microscopy (SEM). In static oxidation, the formed titanium oxide (TiO2) layer was found to have mainly anatase structure at temperatures between 500°C to 600°C and transformed to rutile structure at temperature higher than 600°C. Through this study, oxidation rate and activation energy of oxidation for each sample were evaluated. It was found the samples exhibited a higher activation energy of oxidation could have a higher wear resistance. The role of oxidation mechanism was proved to be critical to the wear of Ti(C, N, O) thin films.