Characteristics and performance of TiSiN/TiAlN multilayers coating synthesized by cathodic arc plasma evaporation

Nano-multilayer TiSiN/TiAlN films have been deposited on WC–Co substrates using TiSi (80:20 at.%) and TiAl (50:50 at.%) alloy target by a dual cathodic arc plasma evaporation system. The influences of lamellae thickness on the microstructure, mechanical, tribological, and corrosive properties of the films were investigated. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction techniques were employed to analyses the microstructure, grain size, residual stress and lamellae thickness. Nano-indentation and tribometer testes were used to measure the mechanical and tribological properties of nano-multilayer TiSiN/TiAlN thin films. The results showed that the hardness of the films ranged from 32–38 GPa, with a higher value than TiAlN (29 GPa). The coefficient of steady-state friction of the films against a bearing steel ball ranged from 0.47 to 0.52, and TiSiN and TiAlN is 0.56 and 0.6, respectively. The potentiodynamic polarization measurements showed that for all the multilayered coatings the corrosion potential shifted to higher values, and the corrosion current density decreased, indicating better corrosion resistance than that of TiAlN single-layer coatings. To summarise, it has been found that the microstructure, mechanical, wear, and corrosion properties of the films were dependent on lamellae thicknesses in film structure, resulting from improved mechanical, wear and corrosion properties of nano-multilayer TiSiN/TiAlN coatings.