V-substituted Ti1-xVxC carbides in comparison with Mono-TiC carbide – A study combining first-principle calculations and experiments

TiC carbide is one of important carbides used as a reinforcement for cutting tools, wear-resistant coatings, composites, and alloys. This study was conducted to investigate the possibility of modifying TiC carbide by partially substituting Ti with V for improved mechanical behavior. Based on the density functional theory calculation and experimental verification, the V-substituted TiC shows improved mechanical properties. The electronic structure and bonding characterization were analyzed to understand the underlying mechanism and relation between the V content and the properties of the V- substituted carbide. It was demonstrated that covalent and ionic bonds both influenced the structural stability and properties. By balancing the contributions of covalent and ionic interactions with the V substitute, the Ti1-xVxC carbide can be designed for optimized properties. Experimentally, the Ti1-xVxC carbides were successfully synthesized. The Ti0.5V0.5C showed the highest hardness and wear resistance. The obtained results show good consistency in hardness and wear test between the calculations and experiments.