Synthesis of nanosized tungsten carbide from phenol formaldehyde resin coated precursors

Nanosized tungsten carbide was synthesized from phenol formaldehyde resin (PF) coated tungsten precursors. The process has three steps in which nanosized tungsten particles were first coated with PF, then the precursors were carburized at 950°C, and finally the carburized powders were treated in flowing wet hydrogen atmosphere at 940°C to remove the uncombined carbon. The obtained powders were characterized using X-ray diffraction analysis (XRD), field-emission scanning electron microscopy (FESEM), small angle X-ray scattering (SAXS), and combustion-gas-volume method. The results indicated that single-phase WC could be synthesized using excessive PF as carburizer at a much lower temperature compared with using mixed carbon black. After wet hydrogen treating, the mean size of the obtained WC particles was 94.5 nm and the total carbon content was 6.18 wt.%.