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

Titanium carbide (TiC) and tungsten carbide (WC) are essential engineering materials known for their exceptional hardness, wear resistance, and thermal stability. This study investigates the formation, phase stability, mechanical properties, and electronic structure of (Ti,W)C solid solutions. The research employs computational methods, including Density Functional Theory (DFT) and Cluster Expansion (CE), to explore compositional variations and their effects. Results reveal that Ti0.5W0.5C demonstrates superior thermodynamic stability, while intermediate compositions such as Ti0.67W0.33C achieve peak hardness (~33 GPa) due to the synergistic effects of covalent Ti-C and metallic W-C bonding. The electronic structure analysis highlights hybridized bonding characteristics that optimize mechanical resilience and thermal stability. Elastic and vibrational properties show a notable influence of tungsten incorporation, enhancing bulk modulus and enabling tailored properties. These findings provide critical insights for the development of high-performance materials in applications such as machining, wear-resistant coatings, and structural components.