Bulk crystallization of glasses belonging to the calcia-zirconia-silica system by microwave energy

This paper reports results that show the effect of microwave absorption on the bulk crystallization of two glasses in the CaO-ZrO2SiO2 system. The gla ss samples were de vitrified using either microwave or conventional heating , to compare the results obtained from the two different techniques. Remark ably different crystallization paths were observed, depending mostly on the composition of the glass. This observation was especially true when microw ave heating was used, where the dielectric losses observed in silicate glas ses are related to the ZrO2 content. X-ray diffraction analysis was perform ed on the powdered samples, to determine the crystalline phases present. Th e microstructure and microanalysis results of these glass-ceramic compositi ons are presented and are related to the different ZrO2 contents.