Effect of Different Nucleating Agents on the Microstructure and Properties of LMAS Glass-Ceramics

Abstract

Li2O-MgO-Al2O3-SiO2(LMAS) system glass-ceramics had been prepared by sintering method. The effect of different nucleating agents on the phase composition, microstructure and properties of LMAS system glass-ceramics were investigated by DTA, XRD and SEM. The results indicate that the introduction of nucleating agents could contribute to decreasing the crystallization temperature of the glass-ceramics, the effect of the nucleating agent TiO2 is most obvious, and the crystallization temperature is the lowest(798.9°C). Main crystal phase of the glass-ceramics without the nucleating agents is β-quartz solid solution, while main crystal phase of the glass-ceramics with different nucleating agents changes into β-spodumene solid solution. The glass-ceramics with composite nucleating agents (TiO2+ZrO2+P2O5) are the lowest coefficient of thermal expansion (0.86×10-6/°C)and the highest flexural strength (95MPa). Composite nucleating agents have the best effect of crystallization, and contribute to the formation of a large number of short columnar crystals, which is the main reason for obtaining glass-ceramics with low expansion coefficient and high flexural strength.