Physico-mechanical properties, structure, and phase composition of (BeO + TiO₂)-ceramics containing TiO₂ nanoparticles (0.1–2.0 wt.%)

This research studies the effects of addition of micro- and nanoparticles of TiO₂ and variations in the firing temperature on the physico-mechanical properties of oxide-beryllium ceramics, shows the evolution of the microstructure of such ceramics during sintering, and presents the data of X-ray phase analysis. It was shown that the addition of TiO₂ nanoparticles leads to a higher density of the ceramic material after sintering due to the interpenetration of TiO₂ and BeO phases, which is caused by an increase in the diffusion mobility of atoms that can in turn be attributed to an increase in the imperfection of the structure and the fraction of grain boundaries. It was found that the presence of nanoparticles contributes to an increase in the apparent density of the material, as well as a decrease in its total and closed porosity; and an increase in the sintering temperature contributes to the transformation of the crystalline structure of TiO₂ into a more conductive Ti₃O₅with an orthorhombic structure. The presence of nanoparticles also promotes self-healing of micropores, which can be explained by the blocking of a certain fraction of the interfaces between BeO particles by nanoparticles and the creation of a diffusion barrier.