DIFFERENTIAL THERMAL ANALYSIS OF THE CRYSTALLIZATION KINETICS IN PERLITE-BASED NANOCRYSTALLINE GLASS-CERAMICS

Abstract

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.

Keywords

• glass-ceramic material
• crystallization kinetics
• activation energy