Non-stoichiometric high-entropy carbide inhibitors for enhanced grain-growth control and performance optimization of WC-10Co cemented carbides

High-entropy carbide (HEC) was introduced into WC–Co cemented carbides to simultaneously enhance microstructural stability, physical properties, oxidation resistance, and radiation tolerance. The influence of carbon stoichiometry of HEC x (0.8, 1.0, and 1.2) on WC grain refinement, density, oxidation behavior, and He irradiation-induced damage evolution was systematically investigated. The results demonstrated that HEC 0.8 with carbon vacancies exhibited the most pronounced grain-growth inhibition effect through enhanced lattice distortion, sluggish diffusion, and grain boundary pinning. As a result, the WC–10Co-HEC 0.8 composite achieved outstanding mechanical properties, including a hardness of 20.7 GPa, fracture toughness of 13.5 MPa·m 1 ᐟ 2 , and flexural strength of 3525 MPa. Furthermore, HEC 0.8 effectively improved oxidation resistance and suppressed irradiation-induced defect evolution by providing abundant defect trapping sites. This work highlights carbon stoichiometry engineering in HECs as a promising strategy for developing WC–Co cemented carbides with superior multifunctional performance.