Low-temperature consolidation of high-entropy (TiVNbTaMo)C_4.5 ceramics with exceptional strength and hardness

Carbides are considered promising candidates for advanced manufacturing applications due to their superior mechanical properties and excellent thermal stability. However, the requirement for high sintering temperatures remains a significant barrier to achieving dense microstructures with refined grain sizes. In this work, high-entropy (TiVNbTaMo)C_4.5 ceramics with a fine average grain size of ~ 434 nm and high relative density were successfully synthesized at a relatively low temperature of 1550 °C via spark plasma sintering. The pronounced reduction in both sintering temperature and grain size is attributed to the high-entropy effect and the lattice distortion introduced by incorporating multiple principal elements with different crystal structures. The resulting ceramics exhibit a high flexural strength of 813 MPa and a Vickers hardness of 39.19 GPa, without sacrificing fracture toughness, thereby overcoming the typical trade-off between hardness and toughness. The effects of grain refinement and solid–solution strengthening on mechanical properties are systematically investigated using advanced microstructural characterization techniques. This study demonstrates an efficient and cost-effective strategy for the fabrication of high-performance high-entropy (TiVNbTaMo)C_4.5 carbide ceramics.