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Synthesis and Characterization of Sol-Gel-Derived Chemical Mullite
J. Roy1, S. Maitra2
1 Camellia Institute of Technology, Badu Road, Kolkata-700129, India
2 Government College of Engineering & Ceramic Technology, Kolkata-700010, India
received December 29, 2013, received in revised form February 9, 2014, accepted February 13, 2014
Vol. 5, No. 1, Pages 57-62 DOI: 10.4416/JCST2013-00046
Abstract
Mullite (3Al2O3·2SiO2) precursor gel was synthesized using aluminum nitrate nonahydrate and liquid sodium silicate as starting materials based on the sol-gel route. The gel was characterized by means of chemical analysis, surface area and bulk density measurements. Fourier transformation infrared spectroscopic (FTIR) and differential thermal analysis (DTA) were performed to study the course of mullitization. The gel was calcined at 800 °C and compacted at 100 MPa pressure. The compacted masses were sintered at different elevated temperatures and subjected to SEM and XRD analysis for microstructure and phase development studies. FTIR studies confirmed the diphasic nature of the gel during its formation. Primary mullitization started at around 980 °C with an average activation energy of . Crystallization of mullite with a lower amount of SiO2 was completed after sintering at 1600 °C.
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Keywords
Sol-gel, mullite, FTIR, differential thermal analysis, microstructure
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