UFAS1 PLATFORM EVENTS, International Conference on Materials Science ICMS2018

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Crystallization kinetics of α-cordierite ceramic from MgO–Al2O3–SiO2–TiO2 glasses using DTA analysis
Ismail LAMARA

Last modified: 2018-08-01

Abstract


The results of studies of crystallization kinetics of α-cordierite ceramics from MgO–Al2O3–SiO2–TiO2 glasses that are obtained via melt cooling using Differential thermal analysis (DTA), Thermogravimetric analysis (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM) are presented. DTA experiments were carried out on samples between room temperature and 1400 °C under argon gas flowing at a rate of 40 cm3/min.  Heating rates of 10, 20, 30, 40, and 50 °C/min were used in this investigation. X-ray diffraction was used to characterize the phase transformations of the sintered powders. The average activation energy values for α-cordierite formation, using DTA results was measured under both isothermal (Johnson–Mehl–Avrami (JMA) theory using Ligero method) and non-isothermal (using Kissinger, Boswell, and Ozawa methods) treatments were found to be equal to 845 and 720 kJ mol-1, respectively. The growth morphology parameters n (Avrami parameter) were found to be almost equal to 1.5, using non-isothermal treatments, and equal to 1.5 using isothermal ( Ligero method ) and m (the numerical factor) was 1.5 obtained by Matusita et al. equation. The growth morphology parameters n and m are both approximated as 1.5, which is an indication of a three dimensional growth from a constant number of nuclei and resulting in a polyhedron -like morphology controlled by diffusion.