The study on the properties of TiC x N 1− x coatings processed by cathodic arc physical vapour deposition

Titanium carbonitride (TiCN) is a popular hard coating for carbide cutting tools in various applications. The properties of TiCN are within its composition and can be controlled by maintaining the C–N ratio within the coating to a certain level. This paper studied the influence of carbon content and coating composition within TiC _x N_1−x coatings with regard to their mechanical properties. The substrate used was tungsten carbide (WC-6Co), which was prepared in-house through a powder metallurgy process, while the TiC _x N_1−x coatings were deposited in-house using cathodic arc physical vapour deposition (CAPVD). TiC _x N_1−x coatings improved the mechanical properties of carbide inserts. An increase in carbon content within TiC _x N_1−x coatings improved surface lubricity, reduced coefficient of friction, improved surface microhardness and increased Young's modulus, but reduced thermal conductivity of carbide inserts. The colour of TiC _x N_1−x coatings also changed with carbon content.