Sol-gel synthesis and characterization of alumina-15%mullite composite nanopowder
Subject Areas :
Ceramics
Ali Sedaghat
1
,
E. Taheri-Nassaj
2
,
G. Soraru
3
,
R. Ceccatob
4
,
T. Ebadzadeh
5
1 - Department of Ceramic, Material and Energy Research Center, karaj, Iran.
2 - Department of Materials Engineering, Tarbiat Modares University, Tehran, Iran.
3 - Department of Materials Engineering and Industrial Technology, University of Trento, Trento, Italy.
4 - Department of Materials Engineering and Industrial Technology, University of Trento, Trento, Italy.
5 - Department of Ceramic, Material and Energy Research Center, karaj, Iran.
Received: 2013-12-11
Accepted : 2014-01-11
Published : 2014-02-01
Keywords:
Sol–gel processes,
Nanocomposites,
Al2O3,
Abstract :
Homogeneous distribution of mullite in the matrix of alumina can be obtained through sol-gel method. In this work, nanopowder of alumina-mullite composite was synthesized with high homogeneity and high purity. So aluminum chloride hexahydrate and tetraethyl orthosilicate were used instead of alumina or mullite nanopowder. Studying the simultaneouse thermal analysis (STA) of mullite precursor reveals two endothermic peaks at 145 and 240°C due to dehydration and removal of the molecular water and the chloride component. An exothermic peak is also detected at 855°C. According to the XRD patterns of alumina-15vol.% mullite precursors calcined at different temperatures, crystallization of transitional alumina phases (γ, κ) occurs approximately at 800°C. Then these phases transform to α alumina approximately at 1000°C. XRD patterns of alumina-15%vol. mullite which were calcined at different temperatures show peaks of mullite relating to 1000°C. The specific surface area of this nanopowder calcined at 900°C was calculated to be 120.9±0.5 m2/g. The nanopowder was observed by TEM.
References:
D. W. Richerson, Modern Ceramic Engineering, M. Dekker 1992, pp. 808-823.
E. Medvedovski, “Alumina–mullite ceramics for structural applications”,Ceram. Int., Vol. 32, 2006, pp. 369–375.
H. H. Luo, F. C. Zhang, S. G. Roberts, “Wear resistance of reaction sintered alumina/mullite composites”, Mat. Sci.Eng.A, Vol. 478, 2008, pp. 270–275.
S. Mezquita, R. Uribe, R. Moreno, C. Baudín, “Influence of mullite additions on thermal shock resistance of dense alumina materials Part 2: Thermal properties and thermal shock behavior”, Brit. Ceram. Trans. Vol. 100. No. 6, 2001, pp. 246-250.
C. Aksel, “The effect of mullite on the mechanical properties and thermal shock behaviour of alumina–mullite refractory materials”,Ceram. Int., Vol. 29, 2003, pp.183–188.
F. C. Zhang, H. H. Luo, S. G. Roberts, “Mechanical properties and microstructure of Al2O3/mullite composite”, J. Mater. Sci. Vol. 42, 2007, pp. 6798–6802.
C. Aksel, “The role of fine alumina and mullite particles on the thermomechanical behaviour of alumina–mullite refractory materials”, Mater. Lett, Vol. 57, 2002, pp. 708–714.
R. Moreno,S. Mezquita, C. Baudín, “Influence of mullite additions on thermal shock resistance of dense alumina materials Part 1: Processing studies”, Brit. Ceram. Trans., Vol. 100, No. 6, 2001, pp. 241-245.
C. W. Won, B. Siffert, “Preparation by sol-gel method of SiO2 and mullite (3Al203.2SiO2) powders and study of their surface characteristics by inverse gas chromatography and zetametry”, Colloid. Surface. A, Vol. 131, 1998, pp. 161-172.
M. Schehl, L. A. Díaz, R. Torrecilla, “Alumina nanocomposites from powder–alkoxide mixtures”, Acta Mater. Vol. 50, 2002, pp. 1125–1139.
S. Sakka, K. Kamiya, “Glasses from metal alcoholates”, J. Non-Cryst. Solids, Vol. 42, 1980, pp. 403-422.
T. Ebadzadeh, “Formation of mullite from precursor powders: sintering, microstructure and mechanical properties”, Mat. Sci.Eng.A, Vol. 355, 2003, pp. 56-61.
R. Roy, “Aids in hydrothermal experimentation. II. Methods of making mixtures for both “dry” and “wet” phase equilibrium studies”, J. Am. Ceram. Soc., Vol. 39, 1956, pp. 145-146.
A. K. Chakraborty, “Aluminosilicate formation in various mixtures of tetra ethyl orthosilicate (TEOS) and aluminum nitrate (ANN)”, Thermochim. Acta, Vol. 427, 2005, pp. 109–116.
H. Schneider, S. Komarneni, Mullite, WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim, 2005, pp. 263-272.
M. Yamane,S. Inoue, A. Yasumori, “Sol–gel transition in the hydrolysis of silicon methoxide”, J. Non-Cryst. Solids, Vol. 63, 1984, pp. 13.
K. Okada, N. Otsuka, “Characterization of spinel phase from SiO2–Al2O3 xerogels and the formation process of mullite”, J. Am. Ceram. Soc., Vol. 69, 1986, pp. 652-656.
A. K. Chakraborty, D. K. “Ghosh Synthesis and 980◦C phase development of some mullite gels”, J. Am. Ceram. Soc., Vol. 71, 1988, pp. 978-987.
Ch. Sh. Hsi, H. Y. Lu, F. S. Yen, “Thermal behaviour of alumina–silica xerogels during calcinations”, J. Am. Ceram. Soc., Vol. 72, 1989, pp. 2208-2210.
A. Yasumori, M. Anma, M. Yamane, “Chemical effects of formamide and N,N-dimethylformamide on the formation of alkoxy-derived silica gel”, Phys. Chem. Glasses, Vol. 30 1989, pp. 193.
T. Heinrich, F. Raether, “Structural characterization and phase development of sol–gel derived mullite and its precursors”, J. Non-Cryst. Solids, Vol. 147/148, 1992, pp.152.
B. E. Yoldas, “Effect of ultrastructure on crystallization of mullite”, J. Mater. Sci., Vol. 27, 1992, pp. 66-67.
H. Schneider, B. Saruhan, D. Voll, L. Merwin, A. Sebald, “Mullite Precursor Phases”, J. Euro.Ceram. Soc., Vol. 11, 1993, pp. 87.
A. K. Chakraborty, “Role of hydrolysis water–alcohol mixture on mullitization of Al2O3–SiO2 monophasic gels”, J. Mater. Sci., Vol. 29, 1994, pp. 6131.
A. K. Chakraborty, “Effect of pH on 980◦C spinel phase—mullite formation of Al2O3–SiO2 gels”, J. Mater. Sci., Vol. 29, 1994, pp. 1558.
Y. X. Huang, A. M. R. Senos, J. Rocha, J. L. Baptista, “Gel formation in mullite precursors obtained via tetra ethyl orthosilicate (TEOS) pre-hydrolysis”, J. Mater. Sci., Vol. 32, 1997, pp. 105.
A. K. Chakraborty, S. Das, “Al–Si spinel phase formation in diphasic mullite gels”,Ceram. Int., Vol. 29, 2003, pp. 27.
H. Kao, W. Wei, “Kinetics and Microstructural Evolution of Heterogeneous Transformation of θ-Alumina to α-Alumina”, J. Am. Ceram. Soc., Vol. 83, No. 2, 2000, pp. 362-368.
F. Rouquerol, J. Rouquerol, K. Sing, Adsorption by Powders and Porous Solids, ACADEMIC PRESS, London, 1999, pp. 440-441.
S. A. Hassanzadeh-Tabrizi, E. Taheri-Nassaj, “Sol–gel synthesis and characterization of Al2O3–CeO2 composite nanopowder”, J. Alloy. Compd., Vol. 494, 2010, pp. 289-294.
A. Sedaghat, E. Taheri-Nassaj, R. Naghizadeh, “An alumina mat with a nano microstructure prepared by centrifugal spinning method”, J. Non-Cryst. Solids, Vol. 352, 2006, pp. 2818-2828.
S. J. Gregg, K. S. W. Sing, Adsorption, Surface Area and Porosity, ACADEMIC PRESS, London, 1982, pp. 35