Effect of carbon content on the microstructure and phases of (Ti,V,Nb,Cr,Mo)Cx high-entropy carbide

High-entropy carbide (Ti,V,Nb,Cr,Mo)Cx with varying carbon content (x = 13–16 wt%) was synthesized using conventional argon sintering at 1800 °C. Homogeneous distribution of elements was obtained at x = 15 wt% of C, while the presence of residual secondary carbide was observed among all samples with varied carbon content. Density of the high-entropy carbides increases with increasing carbon concentration. The results reveal significant changes in both the microstructure and phase composition. A precise carbon window is required to attain homogeneous distribution among the elements to form a stabilized high-entropy facecentered cubic (FCC) phase structure. Deviations from this narrow carbon window lead to the segregation of chromium in the microstructure, which in turn alters the stoichiometry of the high-entropy carbide system.