Microstructure and Properties of Li2O-Al2O3-SiO2-P2O5 Glass-Ceramics

Serials Li2O–Al2O3–SiO2 matrix glasses and glass-ceramics with different content of P2O5 were prepared by conventional melt cooling method and crystallization process. The effects of P2O5 content on microstructure and properties such as viscosity, melting temperature and coefficient of thermal expansion (CTE) of Li2O–Al2O3–SiO2–P2O5 glasses and glass-ceramics were investigated by DSC, XRD, CTE and SEM. The results show the melting temperature and viscosity of LASP matrix glass decreases with the content of P2O5, while the glass will phase-separated when the content of P2O5 is more than 8.0 wt%. The main crystal phase in researched glass-ceramics is beta-spodumene when crystallization temperature is 850°C. The content of P2O5 has no obvious influence on the type of crystal phase in researched glass-ceramics. P2O5 can promote the precipitation and growth of crystals in glass-ceramics, and slightly increase the CTE of matrix glass and glass-ceramics. Virgilite with negative CTE formed first in LASP glass-ceramics at low temperature, and then turned into beta-spodumene with increase of treating temperature.