Properties of Li2O-ZnO-Al2O3-SiO2 glass-ceramic system prepared by spray pyrolysis

Li2O-ZnO-Al2O3-SiO2 (LZAS) glass-ceramic system was studied in the high temperature spray pyrolysis. Small amount of P2O5 was used as nucleation agent. Fine-sized Li2O-ZnO-Al2O3-SiO2 glass powders with amorphous phase and spherical shape were formed by spray pyrolysis at temperatures between 1300 and 1500 degrees C. The mean size of the glass powders prepared at a temperature of 1500 degrees C was 0.7 mu m. The glass transition temperature (T-g) of the glass powders was 551.2 degrees C. The two crystallization exothermic peaks were observed at 703.8 and 923.8 degrees C. Densifications of specimens occurred at sintering temperatures of 800 and 900 degrees C, in which interconnected network microstructure was formed by tiny dendritic crystals. The specimens sintered at temperatures of 600 and 700 degrees C had LiAl(SiO3)(2) crystal structure. On the other hand, the specimens sintered at temperatures between 800 and 1000 degrees C had LiAlSi2O6 (beta-spodumene) crystal structure. (C) 2008 The Ceramic Society of Japan. All rights reserved.