Enhanced properties of binderless titanium carbonitride based ceramic nanocomposites: An integrated study of microstructure, performance, and mechanisms

Traditional cermets face challenges due to brittleness and temperature sensitivity. This study introduces a novel solid solution strengthening strategy, achieved through nanoparticle hybridization and optimization of sintering parameters, to develop binderless titanium carbonitride nanocomposites (BTC) with enhanced tribological and thermomechanical properties. By tailoring the dense microstructure through hybrid nanoparticles and optimized sintering conditions, BTC achieves exceptional mechanical properties, a flexural strength of 948 ± 167 MPa, Vickers hardness of 20.17 ± 0.95 GPa, and fracture toughness of 6.66 ± 1.03 MPa·m¹/², exceeding the composites containing only single nanoparticle by 106.9 %, 17.7 %, and 105.4 %, respectively. Notably, it achieves 11.01 % lower friction coefficient and 26.84 % reduced wear rate compared to commercial WC-6Co under dry sliding. Even at 1000 °C, a high hardness of 9.32 ± 0.20 GPa is retained. Moreover, through detailed microscopic characterization of friction and wear, the specific mechanisms behind these performance enhancements are clearly elucidated. Additionally, the experimental analysis and theoretical modeling quantitatively unveil the microstructure evolution, toughening and strengthening mechanisms in BTC. Consequently, the present study provides robust foundation for the development of advanced titanium carbonitride based composites.