2008 Volume 49 Issue 7 Pages 1594-1599
The effect of high-energy milling on the phase transformation and carbothermal reduction was examined using an oxide mixture, TiO2-WO3-NiO-C, with a process to synthesize (Ti,W)C cermets. Due to the high energy involved in the mill raw, anatase TiO2 transformed first to TiO2-II and then to rutile, while WO3 transformed to a high-pressure WO3-HP and hexagonal WO3 phase. The co-existence of WO3 and TiO2 enhanced the formation of a nano-crystalline or amorphous phase. The (Ti,W)C phase was formed mainly at 1150°C from TiC and WC formed in the early stages. These results were further examined using XRD, the Rietveld method and mass spectroscopy.