Structure, Mechanical Properties, and High-Temperature Oxidation Resistance of Multicomponent Nitride, Carbide, and Carbonitride Coatings Based on the (AlCrNbSiTi)X (X = N, C, CN) System

This study systematically investigates the influence of the non-metallic component type (X = N, C, CN) and deposition parameters (temperature, bias potential) on the structure, mechanical properties, and high-temperature oxidation resistance of multicomponent (AlCrNbSiTi)X coatings. The coatings were synthesized by reactive magnetron sputtering and characterized using SEM, XRD, instrumented indentation testing, and TGA (1300 °C). It was established that (AlCrNbSiTi)N nitride coatings surpass their carbide and carbonitride counterparts in both hardness (up to 47 GPa) and oxidation resistance. The bias potential was identified as a key factor determining the oxidation mechanism; a -40 V bias initiates a transition from through-thickness oxidation to protective passivation by forming a dense oxide layer. Furthermore, the optimal condition (no heating, -40 V) creates a nanostructure (25 nm crystallite size), enabling a synergy of ultra-high hardness and maximum oxidation resistance due to rapid Al and Cr diffusion. These results demonstrate the potential for purposefully controlling the high-temperature performance and mechanical properties of multicomponent nitride coatings by managing ion bombardment and microstructure.