Characterisation of TiCxOy thin films produced by PVD techniques

Purpose: The purpose of this work consists in the characterisation of TiCxOy thin films produced by dc reactive magnetron sputtering. The main goal consists in studying the influence of the reactive gas flow in the atomic composition, structure, colour and electrical and mechanical properties of the films. Design/methodology/approach: All the deposition parameters were maintained constant except the reactive gas flow. After deposition, the properties of the coatings were measured and were related with variation of reactive gas flow. Findings: The results show that the films properties subsist into 3 different regimes - i) carbide, ii) a transition zone and iii) an oxide one. The colour results indicate a strong dependence on the O/Ti ratio. A progressive reduction of hardness and residual stresses with increasing of the O/Ti ratio was observed. The residual stresses, as well as the film structure, seem to play an important role on the adhesion of the coatings. Research limitations/implications: The main limitation of this work is linked to the deposition technique itself. It is difficult to avoid surface defects and pinholes that strongly influence the tribological results. Practical implications: TiCxOy thin films are multifunctional due to present good electrical and optical properties but also good mechanical properties which allow them to be used in several applications; from decorative to electronic applications. Originality/value: There is a new class of coatings where the research of TiCxOy thin films is included: the multifunctional coatings. This class of coatings should be easy to prepare and to tune the properties as function of particular applications. This characteristic may be extremly important to advanced coatings industry.