Fabrication of Densified W-Ti by Reaction Treatment and Spark Plasma Sintering of WO3-TiH2 Powder Mixtures

W-10 wt% Ti alloys that have a homogeneous microstructure are prepared by thermal decomposition of WO3-TiH2 powder mixtures and spark plasma sintering. The reduction and dehydrogenation behavior of WO3 and TiH2 are analyzed by temperature programmed reduction and a thermogravimetric method, respectively. The X-ray diffraction analysis of the powder mixture, heat-treated in an argon atmosphere, shows W-oxides and TiO2 peaks. Conversely, the powder mixtures heated in a hydrogen atmosphere are composed of W, WO2 and TiO2 phases at 600 degrees C and W and W-rich beta phases at 800 degrees C. The densified specimen by spark plasma sintering at 1500 degrees C in a vacuum using hydrogen-reduced WO3-TiH2 powder mixtures shows a Vickers hardness value of 4.6 GPa and a homogeneous microstructure with pure W, beta and Ti phases. The phase evolution dependent on the atmosphere and temperature is explained by the thermal decomposition and reaction behavior of WO3 and TiH2.