Phase and microstructure evolution during the synthesis of WC nanopowders via thermal processing of the precursor

► Nano-WC powders were successfully synthesized at only 1000 °C for 2 h. ► Phase evolution of WO3 follows mainly WO3 → WO2.9 → WO2.72 → WO2 → W → WC. ► Significant grain growth of WC powders occurs at 1200-1300 °C.