Abstract
Based on the poudretteite (K Na-2 B-3 Si-12 O-30) glass composition, six transparent glass frits were prepared. TiO2, LiF and Cr2O3 were experimented on the base glass composition as nucleation catalysts. Only cristobalite and tridymite were developed through the sintering process of the glasses between 900 and 1100 A degrees C. LiF enhances mainly tridymite with traces of cristobalite and in the opposite side the parent and both TiO2 and Cr2O3 containing glasses catalyzed mainly cristobalite with traces of tridymite. The microstructure of the glass samples heat-treated at 1000 A degrees C showed backbone-like, small rods, quadrant-, hexagonal crystals referred to the cristobalite and tridymite. The EDS microanalysis shows the presence of both alkalis, i.e. Na (+) and K (+) , in the cristobalite crystal structure while the residual glass contains K (+) . The infrared spectroscopy indicates the band patterns of cristobalite and tridymite.