Differential thermal analysis of the crystallization kinetics in perlite-based nanocrystalline glass-ceramics

A glass-ceramic material containing nanosized crystallites is synthesized based on the natural volcanic material perlite. Using the differential thermal analysis (DTA) method, the effect of Na2SiF6 (a crystallization catalyst from the fluoride group) on the glass crystallization properties is studied. The characteristic glass-transition temperature Tg, peak crystallization temperature Tp, as well as the crystallization activation energy (Ec) and Avrami index (n) are determined in terms of the catalyst content in the initial composition. A decrease in the nucleation agent content is shown to increase Tg, Tp, and Ec. The effect of the crystallization catalyst content on the crystallization mechanism and glass mechanical properties is discussed.