Enhanced properties of (TaNbTiV)C high-entropy carbide ceramics through controlled structure and morphology of high-entropy carbide powders

Submicron high-entropy carbide (HEC) (TaNbTiV)C powders with various morphologies and properties were prepared using the molten salt method by adjusting structures and graphitization of carbon sources. Subsequently, the HEC ceramics were sintered at 1900°C using spark plasma sintering. Compared to traditional carbon sources (carbon black and flake graphite), powders synthesized using graphitic carbon microspheres with a spherical shape exhibited a smaller particle size of 0.45 µm, a larger specific surface area of 14.46 m²/g, and a larger lattice constant of 0.4451 nm. Moreover, the HEC powders prepared using graphitic carbon microspheres enhanced the sintering of the HEC matrix, leading to improved mechanical properties and oxidation resistance of the HEC ceramics compared to those prepared using other carbon sources. Unlike the precursor method used to adjust the HEC powder structure, the molten salt method is a low-cost and straightforward approach to regulating the HEC powder structure by controlling the structure of raw material.