Synthesis of novel single-phase high-entropy metal carbonitride ceramic powders

Abstract Single-phase high-entropy metal carbonitride (HECN) powders, namely (HfZrTaNbTi)(C,N), were successfully synthesized via a facile high-energy ball milling assisted carbothermal reduction nitridation at the temperature above 1400 °C in a flowing N2 atmosphere for the first time. The as-prepared HECN powders had a single-crystalline structure of metal carbonitride and simultaneously possessed high compositional uniformity. The increasing temperature from 1400 °C to 1600 °C promoted the grain growth of HECN powders from 0.31 μm to 1.26 μm. The low oxygen content of 0.494 wt% was obtained for as-prepared HECN powders at 1600 °C. This work is the first report of preparing a high-entropy metal carbonitride powders using metal oxides and carbon as raw materials.