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

Abstract

Serials Li 2 O-Al 2 O 3 -SiO 2 matrix glasses and glass-ceramics with different content of P 2 O 5 were prepared by conventional melt cooling method and crystallization process.The effects of P 2 O 5 content on microstructure and properties such as viscosity, melting temperature and coefficient of thermal expansion (CTE) of Li 2 O-Al 2 O 3 -SiO 2 -P 2 O 5 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 P 2 O 5 , while the glass will phase-separated when the content of P 2 O 5 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 P 2 O 5 has no obvious influence on the type of crystal phase in researched glass-ceramics.P 2 O 5 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.