Nucleation, crystallization behavior and microstructure of mica glass-ceramics in the system SrO·4MgO·xAl2O3·6SiO2·2MgF2 (x=1, 1.5 and 2)

The effect of varying Al2O3 content on the crystallization and microstructure behavior of strontium containing glasses based on the system SrO·4MgO·Al2O3·6SiO2·2MgF2 was investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The glass transition temperature (Tg) and first crystallization peak temperature (Tp1) reduced with decrease in the alumina content. Glasses with x≥1.5 exhibited a second crystallization peak temperature (Tp2). The first crystallization peak temperature (Tp1) corresponded to the formation of strontium fluorophlogopite and second crystallization peak temperature (Tp2) corresponded to the formation of strontium aluminum silicate.