Dehydrogenation of TiH2

Hydrogen is a unique alloying element for titanium because it can be introduced into the metal to form solid solutions or stoichiometric compounds by exposure to the gas at elevated temperatures and removed by vacuum annealing. Studies on dehydrogenation of fine titanium hydride are important for several applications such as thermohydrogen processing of Ti and Ti based alloy components, hydrogen storage materials and bonding of metals and ceramics using TiH2. Effect of particle size on dehydrogenation of TiH2 is studied here, using thermal analysis along with structural investigations. Dehydrogenation of nanocrystalline hydride powder differs considerably from the micron size starting powder. A two step dehydrogenation process, (TiH2 → TiHx → α-Ti) where 0.7<x<1.1, is observed and thermal stability of TiHx at high temperatures is suggested.