2010 Volume 57 Issue 5 Pages 348-351
High purity and nano-sized tungsten carbide (WC) particles have been successfully prepared using chemical complex solution which is composed of tungstic acid, citric acid and ammonia solution. The precursor, which was obtained by drying the chemical complex solution, was heated to 1423 K under Ar atmosphere. Total carbon (C) amount of the heat-treated precursor was controlled by molar ratio of citric acid and tungstic acid. In case of this experimental system, W-C bonds have been already formed at 723 K. The carbonization temperature was lower than that of the conventional methods that used C and WO3 or W, therefore particle growth has been suppressed. The sizes of the obtained WC particles were under 100 nm and the amounts of iron and cobalt as impurities were under 10 ppm.
