EFFECTS OF THE SiO₂-B₂O₃ RATIO ON THE STRUCTURE AND PROPERTIES OF B₂O₃-ZnO-SiO₂-BaO-LiO₂-Al₂O₃-Na₂O-CaO PARENT GLASS AND GLASS-CERAMICS

The experimental results show that a decrease in the SiO₂/B₂O₃ ration reduced the glass transition temperature, but had little effect on the crystallisation temperature. The basic glass powder pressed into strip samples were sintered at a temperature of 630 to 690 °C. With a decrease in the SiO₂/B₂O₃ ratio, the structure of glass and glass-ceramics changed, and the same change also occurred in the crystal phase in the glass-ceramics. When the SiO₂/B₂O₃ ratio was 0.29, the glass-ceramics sintered at 670 °C reached the best properties, including the bending strength, density, and acid resistance. When the SiO₂/B₂O₃ ratio was 0.29, the coefficient of thermal expansion of the glass-ceramics sintered at different temperatures were maintained in the range of 6.3∼7.2×10-6 K-1.