Characterization and crystallization mechanism of SiO₂-Al₂O₃-Li₂O glass–ceramic using non-isothermal models

Abstract

In this paper we investigate the impact of ZrO₂ and TiO₂ as nucleating agents on the crystallization behavior of a lithium aluminosilicate (LAS) glass–ceramic (G-C). The crystallization mechanism is explored at first through X-ray diffraction analyses next to various heat treatments. Differential scanning calorimetry (DSC) analyses conducted under non-isothermal conditions at different heating rates reveal well-defined exothermic peaks. The activation energy (Ea), the key parameter in understanding thermal kinetics, is determined through model-free methods, specifically Flynn Wall Ozawa (FWO) and Kissinger Akahira Sunose (KAS), as well as the model-fitting approach (Coats-Redfern, C–R method). Additionally, the crystallization mechanism of the studied LAS glass ceramic is discussed utilizing the C–R method and Criado’s methods. By employing these techniques, a comprehensive analysis of the LAS glass–ceramic system is provided, contributing to the fundamental understanding of its crystallization processes, and laying the groundwork for further advancements in G–C materials.