Synthesis of single-phase (ZrTiTaNbMo)C high-entropy carbide powders via magnesiothermic reduction process.

Preparation of high-entropy carbides in bulk quantities and in powder form via simple methods at relatively low temperature is challenging. Here, we report the first synthesis of (ZrTiTaNbMo)C high-entropy carbide (HEC) powders via magnesiothermic reduction process. In this, a mixture of individual metallic oxides, graphite and magnesium is treated at a temperature of 1350 °C under Ar atmosphere. The (ZrTiTaNbMo)C powders are obtained after acid leaching, deionized water cleaning and drying process, and synthesized powders shows single-phase face-centered cubic (fcc) structure with the oxygen content of only 0.35 wt% and particle-size range of 5–60 µm. Such powders are in potential demand for additive manufacturing techniques, while high dense HEC bulk ceramic is fabricated by hot pressing sintering using ball-milled HEC powders in preliminary researches. The successful synthesis of (ZrTiTaNbMo)C powders may guide the way towards synthesis of many other high-entropy carbide powders via magnesiothermic reduction process. • Magnesiothermic reduction was used to prepare single-phase (ZrTiTaNbMo)C powders. • The oxygen content of (ZrTiTaNbMo)C powders was as low as 0.35 wt%. • As-prepared (ZrTiTaNbMo)C powders possessed high compositional uniformity. • High dense (ZrTiTaNbMo)C bulk ceramic with hardness of 22.0 ± 1.7 GPa was obtained. [ABSTRACT FROM AUTHOR]