Synthesis of high entropy carbide ceramics via polymer precursor route

High entropy carbide ceramics with low entropy-forming-ability (EFA), (Ti, Zr, Hf, Mo, W)C and (Zr, Hf, Ta, Mo, W)C abbreviated as HEC-1 and HEC-2 were firstly prepared via pyrolysis of soluble homogeneous polymer precursors at 1800 °C. The as-obtained high entropy ceramics powders exhibit a face-centered-cubic (FCC) structure with equal metal proportion as that of raw materials, and oxygen contents were identified as low as 0.29 wt% and 0.5 wt% for HEC-1 and HEC-2, respectively. Uniform micromorphology and elemental homogeneity were further confirmed at atomic scale. The pyrolysis process was characterized in detail and the results revealed that nano sized oxide solid solutions were generated as intermediate phases with well-distributed elements. The oxidation onset temperature for HEC-1 and HEC-2 powders were 447.23 °C and 545.75 °C, respectively.