International Journal of Hydrogen Energy, Vol.36, No.1, 1276-1286, 2011
Ti3Al destructive hydrogenation
In the present paper it was determined, that interaction between alpha(2)-Ti3Al alloy and hydrogen in temperature range between 298 and 1533 K is performed in accordance with the reaction of the destructive hydrogenation and its products are titanium hydrides and intermetallic compounds Al-enriched in comparison with Ti3Al. The structurally-phasemechanism of alpha(2)-Ti3Al destructive hydrogenation consists in the following. From the beginning solution of hydrogen in Ti3Al leads to disordering of its crystalline structure. Then hydrogen interacts not with the disordered alloy, but with titanium, which goes out from Ti3Al, accordingly to the scheme: TiH2(bct) -> TiH1,9(fcc) -> beta-Ti-H-y(bcc) -> alpha-Ti-H-x (hexagonal) -> alpha-Ti (hexagonal). The intermetallic compounds with the enhanced aluminum content are arised, when suitable stoichiometric concentrations are formed. The monolithic composites with nano-size components were obtained by means of Ti3Al destructive hydrogenation at 973 K during 1 and 4 h. Their phase compositions were Ti3Al-(alpha-TiH-Ti3-xAl) and ((alpha-Ti-H-x)-(beta-Ti-H-y)-TiH1,9(fcc)-TiH2(bct))-(Ti3Al-TiAl-TiAl2) correspondingly. These composites consist of continuous matrixes and inclusions situated in them. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.