Kucheriavyj O. Physico-chemical regularities of destructive hydrogenation of intermetallics from Ti-Cu, Ti-Co, Ti-Ni systems.

The thesis is devoted to the thermobaric conditions and structure-diffusion processes of destructive hydrogenation of intermetallic in the Ti-Cu, Ti-Co, Ti-Ni systems as well as synthesis of functional nanostructured composites based on titanium hydride. A thermodynamic analysis of the investigated intermetallic compounds reactions with hydrogen was carried out. Phase mechanism of titanium intermetallics destructive hydrogenation is established. It consist of sequential hydrogen dissolving in intermetallics, selective hydrogenation of titanium to fcc titanium hydride and formation of titanium depleted phases in accordance with corresponding Ti-Cu (Co, Ni) phase diagrams. The indestructible nanocomposites of matrix structure with titanium hydride inclusions were obtained. The conditions and mechanism of recombination of destructive hydrogenation products in vacuum and hydrogen were investigated. The initial compositions of the investigated intermetallics were experimentally restored at 1073 K. It is shown that the total reaction rate of destructive hydrogenation of intermetallics in Ti-Cu, Ti-Co, Ti-Ni systems is limited mainly by the hydrogen diffusion in intermetallics and increases with temperature, hydrogen pressure, nickel content in Ti Ni intermetallics, and titanium content in Ti Cu intermetallics. The destructive hydrogenation reaction of Ti-Cu system intermetallics was used for the synthesis of non-destructive TiH1,9 - Cu composites with 2-3 times increased hydrogen capacity compared with intermetallic hydrides and for making of Ti2Ni based detonation coatings with improved mechanical strength.