Preparation and mechanical properties of gel-cast Ti(C,N)-CoCrCuFeNi cermets

Ti(C,N)-based cermets are widely used in cutting tools and high-temperature structural components, but their application is limited by difficulties in fabricating large and complex-shaped parts. In this study, Ti(C,N)-based cermets were prepared via gel-cast using a CoCrCuFeNi high-entropy alloy (HEA) as the binder. The effects of solid loading on slurry stability and green body formation, as well as the influence of sintering temperature on microstructure and mechanical properties, were investigated. The results show that stable slurry and uniform green bodies were obtained at a solid loading of 55 vol%. With increasing sintering temperature, densification and mechanical properties improved concurrently, while the fracture mechanism transitioned from intergranular fracture to matrix tearing. The Ti(C,N)-based cermet sintered at 1550 °C for 60 min exhibited excellent properties, with a relative density of 96.42%, hardness of 1665.67 HV30, bending strength of 671.75 MPa, and fracture toughness of 6.44 MPa m 1/2 , comparable to conventional Ti(C,N)-Ni cermets. These results demonstrate that gel-cast with a HEA binder is a promising approach for fabricating large, complex-shaped Ti(C,N)-based cermets.