Gelation, Phase-Formation, and Sintering Processes in the Sol-Gel Method of Producing Aluminosilicate Glass-Ceramic Modified by Refractory Hafnium and Zirconium Oxides

Abstract

Glass-ceramic based on compositions in the system Sr(Ba)–Al₂O₃–SiO₂, modified by additions of zirconium oxide ZrO₂ and hafnium oxide HfO₂ with and without yttrium as a stabilizer, was synthesized by the sol-gel method. It was shown that the introduction of refractory oxides shortens the gelation time of the initial solutions, intensifies the sintering of the glass-ceramic, and changes the temperature intervals of phase formation processes and the nature of the precipitated crystalline phases. The sol-gel method made it possible to obtain a uniform distribution of the modifier-oxide grains in the bulk of the glass-ceramic. The yttrium oxide in the structure of the materials is concentrated near ZrO₂ and HfO₂ particles.