First-Principles Study of the Mechanical Properties of (Ti, W)C Solid Solutions

The phase stability, mechanical properties, and electronic structure of (Ti, W)C solid solutions are computationally investigated, specifically, by density functional theory (DFT) and the cluster expansion method, with a focus on composition variations and their effect on the properties. The results reveal that Ti0.5W0.5C exhibits higher thermodynamic stability, whereas intermediate compositions, such as Ti0.67W0.33C achieve peak hardness (~33 GPa) due to the synergistic effect of Ti–C covalent and W–C metallic bonds. Electronic structure analysis reveals that the bonds have a hybridized nature, which impart the material with mechanical resilience and thermal stability. The introduction of tungsten exerts a pronounced influence on elastic and vibrational properties, enhances the bulk modulus, and enables the tailored tuning of material properties. These findings provide an important scientific foundation for the design of high-performance materials for application in metal cutting, wear-resistant coatings, and structural components.