Conversion of W2C to WC phase during mechano-chemical synthesis of nano-size WC-Al2O3 powder using WO3-2Al-(1Â +Â x)C mixtures

► WC-Al2O3 composite powder (free from W2C phase) was mechano-chemically synthesized by use of WO3-2Al-1.8C mixture. ► Thermodynamic calculations and supplementary experiments in W-yC and W2C-C systems were used to clarify the reaction mechanism. ► It was found that the excess carbon amount in the mixture, promotes the W2C to WC phase conversion. ► The produced WC-Al2O3 powder contains nano-size phases.