Controlled Crystallization of and Spherulitic Morphology in Li2O.2SiO2-BaO.2SiO2Glasses

Abstract

The crystallization process of Li2O.2SiO2-BaO.2SiO2 glasses was investigated using DTA, XRD and SEM methods. The incorporation of P2O5 did not result in volume crystallization; a surface crystallization was dominant for all the compositions studied according to DTA data. Lithium disilicate, barium disilicate and different forms of SiO2 were the identified phases after two-stage heat treatment. The spherulitic morphology was observed by SEM after primary crystallization temperature. After the crystallization of barium disilicate phase, the spherulitic morphology disappeared and massive polycrystalline microstructures were formed.