Abstract
Mullite, 3A12O3 · 2SiO2, was synthesized by heat-treating homogeneous sol-gel-derived mixtures of A12O3 and SiO2 taken in stoichiometric amounts. To reduce the mullitization temperature, sols containing γ-AlOOH and SiO2 nanoparticles (2 to 20 nm) were used in the preparation of the mullite precursors. A few samples were made using the products of hydrolysis of aluminum salts instead of the γ-AlOOH sol. The process parameters determining the homogeneity of the precursor mixtures were revealed. The preparation conditions ensuring mullite crystallization at temperatures between 1200 and 1250°C were found. The results are discussed in terms of the reaction between A12O3 and SiO2 during mullitization.
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References
Hong, J.S., Huang, X.X., and Guo, J.K., Synthesis and Sintered Properties of Mullite Powder from Seeded Diphasic Al2O3-SiO2 Gel,Mater. Lett., 1995, vol. 24, pp. 327–331.
Balkevich, V.L., Belyakov, A.V., and Men’kova, E.R., Synthesis and Sintering of Pure Mullite,Tr. Inst.-Mosk. Khim.-Tekhnol. Inst. im. D. I. Mendeleeva, 1983, no. 128, pp. 54–59.
Pach, L., Iratni, A., Hrabe, Z., Svetik, S., and Komarneni, S., Sintering and Crystallization of Mullite in Diphasic Gels,J. Mater. Sci., 1995, vol. 30, pp. 5490–5494.
Okada, K. and Otsuka, N., Change in Chemical Composition of Mullite Formed from SiO2-Al2O3 Xerogel during the Formation Process,J. Am. Ceram. Soc., 1987, vol. 70, no. 10, pp. C245-C247.
Yoldas, B.E. and Partlow, D.P., Formation of Mullite and Other Alumina-Based Ceramics via Hydrolytic Polycondensation of Alkoxides and Resultant Ultra- and Microstructural Effects,J. Mater. Sci., 1988, vol. 23, no. 5, pp. 1895–1900.
Wei, W.C. and Halloran, J.W., Phase Transformation of Diphasic Aluminosilicate Gels,J. Am. Ceram. Soc., 1988, vol. 71, no. 3, pp. 166–172.
Huling, J.C. and Messing, G.L., Hybrid Gels for Homoepitactic Nucleation of Mullite,J. Am. Ceram. Soc., 1989, vol. 72, no. 9, pp. 1725–1729.
Sundaresan, S. and Aksay, J.A., Mullitization of Diphasic Alumosilicate Gels,J. Am. Ceram. Soc., 1991, vol. 74, no. 10, pp. 2388–2392.
Shabanova, N.A., Synthesis and Aggregative Stability of Concentrated Silica Hydrosols,Doctoral (Chem.) Dissertation, Moscow, 1985.
Iler, R.K.,The Chemistry of Silica, New York: Wiley, 1979. Translated under the titleKhimiya kremnezema, Moscow: Mir, 1982.
Shel, R., Control of the Porous Structure of Amorphous Silica-Alumina: 2. The Effect of pH and Reactant Concentration,Appl. Catal., 1984, vol. 12, pp. 189–200.
Timoshchuk, E.A., Loginov, A.F., Bazhenov, A.V.,et al., Stability of A12O3 Hydrosols,Tr. IREA, 1991, no. 53, pp. 16–19.
James, I., Douy, A., and Massiot, D., Synthesis of a Mullite Precursor from Aluminum Nitrate and Tetraethoxysilane via Aqueous Homogeneous Precipitation: An27Al and29Si Liquid- and Solid-State NMR Spectroscopic Study,J. Am. Ceram. Soc., 1995, vol. 78, no. 10, pp. 2648–2654.
Wei, W.C. and Halloran, J.W., Transformation Kinetics of Diphasic Aluminosilicate Gels,J. Am. Ceram. Soc., 1988, vol. 71, no. 7, pp. 581–587.
Huling, J.C. and Messing, G.L., Epitactic Nucleation of Spinel in Aluminosilicate Gels and Its Effect on Mullite Crystallization,J. Am. Ceram. Soc., 1991, vol. 74, no. 10, pp. 2374–2381.
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Vol’khin, V.V., Kazakova, I.L., Pongratz, P. et al. Mullite formation from highly homogeneous mixtures of Al2O3 and SiO2 . Inorg Mater 36, 375–379 (2000). https://doi.org/10.1007/BF02758084
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DOI: https://doi.org/10.1007/BF02758084