Improving the radiation-thermal stability of titanium hydride

Abstract

The paper presents the results of studies of the thermal stability of titanium hydride and titanium hydride containing a borosilicate framework. It is shown that the presence of chemically attached boron atoms on the surface of titanium hydride particles increases the initial dissociation temperature of titanium hydride. The phase composition and imperfection of titanium hydride crystals in the temperature range of 100-700 °C were studied. An increase in the defectiveness of the structure of a titanium hydride crystal during its heat treatment is shown. Mechanisms for modifying the surface of titanium hydride by surface assembly and the creation of a borosilicate framework have been established. It was shown that the ongoing structural-phase transformations in the borosilicate coating activate solid-phase interactions and contribute to the fixation of borosilicate. Based on the data of thermogravimetric analysis, it was shown that the modification of titanium hydride increases its thermal stability by 185 °C, shifting the onset of dehydrogenation processes to the high-temperature region from 463 °C to 649 °C.

Increasing the Adherence of Metallic Copper to the Surface of Titanium Hydride

“…Metal hydrides that have temperature stability in the high-temperature range (up to 800 • C) are the most promising [3,4]. The main attention should be paid to titanium hydride (TiH 2 ), which contains a large number of hydrogen atoms per 1 cm 3 of the metal (9.2 × 10 22 ), second only to vanadium hydride 11.4 × 10 22 [5].…”

“…However, it was shown in [5,12] that spherical titanium hydride has microcracks (20-30 nm) on its surface through which hydrogen can be thermodiffused from the surface layers and from the entire volume of the granules.…”

“…In the presence of spherical cracks on the surface of titanium hydride, the rate of its oxidation and thermal diffusion of hydrogen at 300-400 • C is about two times higher than for granules without cracks [5,13]. Therefore, much attention has been paid to the work aimed at obtaining spherical samples of titanium hydride in which there are no cracks or their numbers are reduced to a minimum.…”

“…The analysis of the available research in this direction [3,4,14] showed that the regulation of the conditions for the production (pressure and temperature conditions) of spherical titanium hydride granules does not solve the problem of the formation of surface microcracks. The most promising method is to "heal" microcracks by artificially creating a multi-barrier system of energy "traps" on the surface of the granule, which makes it possible to slow down the processes of thermal diffusion of hydrogen from the crystal lattice of titanium hydride at high temperatures and protect titanium from oxidation [5,[15][16][17][18][19][20][21][22][23][24][25].…”