EFFECT OF CERIA ADDITION ON SINTERING AND PROPERTIES OF CORDIERITE-BASED GLASS CERAMICS

The effect of CeO2 on the phase transformation, sintering characteristics and properties of cordierite-based glass-ceramics with non-stoichiometric composition prepared by quenching of molten droplets is studied by X-ray diffraction, differential thermal analysis and scanning electron microscopy. The results showed that CeO2 addition obviously prevents the formation of μ-cordierite phase in the glass- ceramics and improves the formation of α-cordierite phase from μ- cordierite. CeO2 addition decreases the sintering activation energy and lowers the sintering temperature of cordierite glass- ceramics. With 4 %(in mass fraction) of CeO2 added, the lowest temperature for μ- to α-cordierite transformation achieved is about 900 ℃, and the glass-ceramics is in sufficient-densification. But too much CeO2 added will inhibit the sintering and crystallization. The flexural strength of the cordierite glass-ceramics increases with the addition of CeO2, and the flexural strength shows a maximum value at 4%of CeO2. The addition of CeO2 has a little effect on the thermal expansion coefficient of the cordierite glass- ceramics. The glass-ceramics is suitable for the applications in low temperature co-fired ceramic (LTCC) substrate with high conductivity, low cost thick-film metals such as Cu and Ag/Pd.