Microstructure and Mechanical and Tribological Performance of (TaTiNbWV)C5-Reinforced Ti(C,N)-Based Cermets

In this study, (TaTiNbWV)C5 high-entropy carbide was synthesized via a carbothermal reduction method, and Ti(C,N)-based cermets with varying carbide contents were fabricated via vacuum pressureless sintering. The effects of carbide content on phase composition, microstructure, mechanical properties, and room-temperature/high-temperature tribological behavior were systematically investigated. The results show that (TaTiNbWV)C5 can be obtained at 1500 °C, and the addition of high-entropy carbide promotes the formation of a complete black-core/white-inner-rim/gray-outer-rim structure, significantly refines the grain size, and reduces lattice mismatch at the core–rim interface. As the carbide content increases, hardness and flexural strength initially rise and then decline, while fracture toughness gradually decreases. The overall mechanical properties are optimal at 5 wt.% addition, with a hardness of 1788.5 HV10 and a flexural strength of 1394.4 MPa. Furthermore, the incorporation of (TaTiNbWV) C5 reduces the room-temperature wear rate by one order of magnitude compared to the base material.