The effect of synthesis conditions on structure and phase formation during SHS-hydrogenation of titanium

Abstract

The SHS-hydrogenetion process of titanium sponge has been investigated under the conditions of hydrogen deficiency and excess. Using the time- of-flight mass spectrometry, H + non-uniform distribution thorugh the sponge volume during synthesis under the conditions of H 2 deficiency and H + uniform distribution under the conditions of H 2 excess is obtained. The compositions of the hydrogenated sponge are accordingly TiH 1,5 + Ti and TiH 2 . The structure of Ti-sponge surface before and after SHS-hydrogenetion is compared by SEM. Increase in hydrogenated sponge structure foliation ir- respective of H 2 contents is observed as compared with the initial sponge. The layers acquire correct geometric shape; they are arranged in a certain order, which motive is iterated. Distances between layers vary from micrometer ones to nanosized ones. The phase formation mechanism during ti- tanium hydrogenation is studied by time-resolved X -ray diffraction. Finished product formation passes through a number of intermediate phases ac- cording to solid-phase mechanism: α-Ti α-Ti[H] β-Ti[H] TiH 2 .