Effect of Fe2O3 on non-isothermal crystallization of CaO-MgO-Al2O3-SiO2 glass
(1. National Engineering Laboratory of Vacuum Metallurgy,
Key Laboratory of Nonferrous Metal Vacuum Metallurgy of Yunnan Province,
Faculty of Metallurgical and Energy Engineering,
Kunming University of Science and Technology, Kunming 650093, China;
2. State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization,
Kunming University of Science and Technology, Kunming 650093, China;
3. Faculty of Science, Kunming University of Science and Technology, Kunming 650500, China)
Key Laboratory of Nonferrous Metal Vacuum Metallurgy of Yunnan Province,
Faculty of Metallurgical and Energy Engineering,
Kunming University of Science and Technology, Kunming 650093, China;
2. State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization,
Kunming University of Science and Technology, Kunming 650093, China;
3. Faculty of Science, Kunming University of Science and Technology, Kunming 650500, China)
Abstract: The crystallization behavior and kinetics of CaO-MgO-Al2O3-SiO2 (CMAS) glass with the Fe2O3 content ranging from zero to 5% were investigated by differential scanning calorimetry (DSC). The structure and phase analyses were made by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The experiment results show that the endothermic peak temperature about 760 °C is associated with transition and the exothermic peak temperature about 1000 °C is associated with crystallization. The crystallization peak temperature decreases with increasing the Fe2O3 content. The crystallization mechanism is changed from two-dimensional crystallization to one-dimensional growth, and the intensity of diopside peaks becomes stronger gradually. There is a saltation for the crystallization temperature with the addition of 0.5% Fe2O3 due to the decomposition of Fe2O3. Si—O—Si, O—Si—O and T—O—T (T=Si, Fe, Al) linkages are observed in Fe2O3-CaO-MgO-Al2O3-SiO2 glass.
Key words: CaO-MgO-Al2O3-SiO2 glass; Fe2O3; diopside; crystallization; kinetics