스폰지 티타늄의 수소화 거동

Abstract

Titanium powders have been usually produced by de-hydrogenating treatment in vacuum with titanium hydride (TiH2) powders prepared by milling of hydrogenated sponge titanium, TiHx. The higher stoichiometry of x in TiHx, whose maximum value is 2, is achieved, crushing behavior is easier. TiHx powder can be,therefore, easy to manufactured leading to obtain higher recovery factor of it. In addition, contamination of the powder can also minimized by the decrease of milling time. In this study, the hydrogenation behavior of sponge titanium was studied to find the maximum stoichiometry. The maximum stoichiometry in hydride formation of sponge titanium could be obtained at 750oC for 2 hrs leading to the formation of TiH~1.99 and the treating temperatures lower or higher than 750oC caused the poor stoichiometries by the low hydrogen diffusivity and un-stability of TiHx, respectively. Such experimental behavior was compared with thermodynamically calculated one. The hydrogenated TiH1.99 sponge was fully ball-milled under -325 Mesh and the purity of pure titanium powders obtained by de-hydrogenation was about 99.6%.