Thermal approach to evaluate the sintering–crystallization ability in a nepheline–forsterite-based glass-ceramics
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A glass in the SiO2–Al2O3–MgO–Na2O system was formulated using a non-conventional silica source and other pure raw materials. The thermal stability and crystallization mechanism have been studied by means of differential scanning calorimetry (DSC). Besides, the glass ability to sintering–crystallization has been examined by optical dilatometry, a non-contact technique allowing the acquisition of dilatometric data in the viscoelastic temperature region. The experimental data were confirmed with theoretical equations. X-ray diffraction and field emission scanning electron microscopy were used to verify the crystallization study and electron scanning microscopy to examine the fired sample microstructures. The prevalent crystallization mechanism has been evaluated from different parameters derived from characteristic temperatures of non-isothermal DSC curves, namely the working range (ΔT TS), reduced glass transition temperature (T gr), and the dissimilarity in crystallization temperature (ΔT p) between fine (<63 µm) and coarse (fragment) glass samples.
KeywordsGlass-ceramics Nepheline Forsterite Sintering–crystallization Optical dilatometry (ODL) Differential scanning calorimetry (DSC)
The authors thank Eng. Chiara Venturelli (Expert Lab. Service) for her experimental assistance with the optical non-contact dilatometric measures.
- 1.Hölland W, Beall G. Glass–ceramic technology. Westerville: Ed. The American Ceramic Society; 2002.Google Scholar
- 2.Marotta A, Buri A, Branda F. Surface and bulk crystallization in non- isothermal devitrification of glasses. Thermochim Acta. 1980;40(3):397–403.Google Scholar
- 10.Annual report rice: market developments and perspectives. Ente Italiano Risi; Dec. 2014. http://www.enterisi.it.
- 14.Wattanasiriwech D, Polpuak N, Danthaisong P, Wattanasiriwech S. Use of rice husk ash for quartz substitution in stoneware glazes. J Sci Ind Res India. 2008;67:455–60.Google Scholar
- 16.Andreola F, Barbieri L, Bondioli F. Agri-food waste: an opportunity for the heavy clay sector. Brick World Rev. 2010;1:34–40.Google Scholar
- 23.Paganelli M. Double-beam optical dilatometry. Ceram Forum Int. 2004;81(6–7):50–6.Google Scholar
- 29.Larson AC, Von Dreele RB. General structure analysis system (GSAS). Los Alamos National Laboratory Report LAUR. 2000.Google Scholar
- 35.Thakur RL, Thiagarajan S. Studies in catalyzed crystallization of glasses: a DTA method. Cent Glass Ceram Res Inst Bull. 1966;13:33–45.Google Scholar
- 38.Zanotto ED, Weinberg MC. Trends in homogeneous crystal nucleation in oxide glasses. Phys Chem Glasses. 1989;30:186–92.Google Scholar
- 39.English S, Turner WES. The heat expansion of soda-lime glasses. J Soc Glass Technol. 1919;3:238–9.Google Scholar
- 40.Hirose M, Kobayashi T, Maeda K. Transparency and mechanical properties of glass–ceramics including nepheline–kalsilite solid solution. Reports Res. Lab. Asahi Glass Co. Ltd. 2005; 55:1–7.Google Scholar