Avaliação química, microestrutural e tribológica de filmes finos de TiCxNy produzidos por arco catódico para aplicações decorativas

Abstract

The deposition of thin films can be employed to modify and/or functionalize the properties of a material’s surface, improving wear resistance (tribological properties) or changing the resistivity (electrical properties). Moreover, thin films display different colors, which are interesting for decorative applications. Titanium carbonitride thin films (TiCxNy) are known to improve wear resistance, contributing to the lifespan augmentation of industrial tools and for attracting the attention of the industry for the variation of colors that these films can exhibit. Its coloration varies from gold-yellow to dark-gray. The film’s properties and color vary according to the deposition parameters and film stoichiometry. In that sense, the objective of the present work consist in the evaluation of microstructural and tribological properties and color variation produced in titanium carbonitride films, due to the carbon content variation on these films, in turn induced by variation of N2/CH4 ration in the gaseous mixture. The samples were analyzed by X ray Diffraction, Scanning Electron Micrography, Glow Discharge Optical Emission Spectoscopy, Nanoindentation, Nanosclerometry and Spectrophotometry. Results reveal a film color variation from gold-yellow to light-bronze, with gold-yellow being the predominant color for samples with lower carbon content. The diffractograms suggest a FCC structure with isotropic expansion of the unit cell as CH4 is added to the gaseous mixture during the deposition process. The mechanical properties show a hardness reduction with carbon increase in the TiCxNy films structure, on the other hand, scratch resistance is improved with more carbon present during the deposition process. The results obtained in this work show the possibility to produce titanium carbonitride films with different colors and, at the same time, improve its scratching resistance (important property for decorative props) with the increase of carbon content on the film’s structure.