WO₃-TiH₂ 혼합분말의 반응처리 및 방전 플라스마 소결에 의한 W-Ti 치밀체 제조

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 °C and W and W-rich β phases at 800 °C. The densified specimen by spark plasma sintering at 1500 °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, β 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.