Crystallization kinetics of MgO–Al2O3–SiO2 glass-ceramics

The crystallization behavior and microstructure of MgO–Al2O3–SiO2 glasses containing TiO2 were investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The crystallization kinetic parameters including the crystallization apparent activation energy (E) and the Avrami parameter (n) were also measured with Ozawa and Kissinger methods. The results have shown that: The glass first underwent extensive phase separation into titanium-rich droplets in a silica-rich matrix, then magnesium aluminotitanate (MAT) initially precipitated in the droplet phase. As a result the E values of cordierite was decreased, thus the formation of cordierite crystals were promoted.