Tribomechanical Properties of TiSiCN Coatings Obtained by Anodic Evaporation of Titanium and Decomposition of Hexamethyldisilazane in a Discharge in a System with a Self-Heating Hollow Cathode

Abstract

Using the method of reactive anodic evaporation of titanium in an arc discharge in a system with a self-heating hollow cathode in a gas mixture Ar + C₂H₂ + N₂ with the addition of hexamethyldisilazane (HMDS) vapors, dense homogeneous TiSiCN nanocomposite coatings with a thickness of up to 15 µm, a hardness of up to 43 GPa, and a wear coefficient of 2.8 × 10^–14 m²/N were obtained. It has been shown that by changing the pressure, composition, and activation degree of the vapor–gas mixture, it is possible to change the microstructure and properties of the obtained coatings within a wide range. An increase in the fluxes of C₂H₂, N₂, and HMDS, as well as the discharge current leads to an increase in the coating deposition rate. However, coatings with the optimal microhardness and wear resistance were obtained at a low discharge current of 10 A, a relatively low content of C₂H₂ (1 cm³/min) and HMDS (0.3 g/h), exceeding of which leads to a decrease in the hardness of the films and deterioration of their quality, which can be explained by excessive ionic exposure and nonoptimal chemical and phase composition of coatings. The chemical and phase compositions of the obtained coatings were studied. The coating structure is a nanocomposite consisting of TiCN nanocrystallites dissolved in an amorphous SiCN matrix.