Diffusion-thermal phase transformations in titanium hydride containing a multi-quality system of hydrogen traps
Diffusion-thermal phase transformations in a modified titanium hydride containing a multiparting system of hydrogen traps. Modification of titanium hydride was carried out by the method of layer-by-layer electrochemical precipitation of metallic titanium and copper from organic and inorganic solutions of their salts. The creation on the surface of the titanium hydride of a multilayer coating (Ti - Cu) obtained by the electrochemical precipitation method increases the thermal stability of the metal hydride system by 229.7 °C. Methods of X-ray-phase, X-ray structural and electron-probe microanalysis are shown, the constancy of the phase composition of the modified titanium hydride in the temperature range of 100 - 700 °C. The most essential defects of the crystal lattice in a modified titanium hydride occur at a temperature of 500 °C - due to the hydrogenation of the modification titanium shell and blocking the microcrack of the surface with a copper coating, the period of the elementary cell and the volume of the hydride phase crystal volume changes. The largest concentration of hydrogen in the surface layer (up to 87.9 %) occurs in the temperature range of 300 - 500 °C, which ensures the maximum density of defects in the crystal lattice. At 700 °C, a dislocation density decreases and a decrease in the crystal cell parameters associated with the annealing mode of titanium hydride and hydrogen thermal diffusion into the volume of material. A metallic titanium precipitated on the titanium hydride surface is an effective structural trap of hydrogen diffusing to surface layers during thermal heating, and the creation of an additional protective copper sheath prevents the thermal diffusion of hydrogen into the environment.