Exploring the semi‐coherent interface in high‐entropy carbides and β‐SiC ceramics for superior mechanical properties

Abstract Achieving high toughness and high strength in ceramics remains a critical challenge. In this study, high‐entropy carbides (Hf 0.25 Zr 0.25 Ta 0.25 Ti 0.25 )C and β‐SiC (HEC–SiC) powders were synthesized via a polymer‐derived ceramics route, followed by high‐pressure sintering to produce dense HEC–SiC binary ceramics. Both phases exhibit cubic symmetry and a semi‐coherent interface with a local orientation relationship of HEC // β‐SiC and an interface energy of ∼14.37 J/m 2 . The presence of this semi‐coherent interface significantly enhances interfacial bonding and energy dissipation, thereby improving fracture toughness through mechanisms such as interfacial strengthening and stress redistribution. As a result, the HEC–SiC ceramics demonstrate superior mechanical properties compared to conventional high‐entropy carbides.