A Novel Processing Route for Alumina/Mullite-Based Refractory Materials
1 Otto-von-Guericke-University Magdeburg, Institute for Materials and Joining Technology, 39106 Magdeburg/Germany
2 Institute for Industrial Chemistry, 39106 Magdeburg/Germany
Revision 13.01.2016, 01.02.2016
Volume 8, Issue 2, Pages 81 - 85
Abstract
The paper describes a novel processing method for the manufacturing of alumina/mullite composite materials. It makes use of a dissolution process of aluminium isopropylate and a subsequent, but slow increase of the pH value in the processing solution by stepwise addition and decomposition of urotropine. The pH value increase results in a precipitation of aluminium hydroxide, and in the presence of mullite particles and alumina particles a homogeneous solid body is formed after hydrolysis and drying. While it is not possible to obtain intact samples without alumina addition the combined presence of alumina and mullite particles lead to intact and crack-free parts even after sintering at 1650 °C.
Keywords
mullite/alumina composite, alumina precipitation
References
[1] Schneider, H.; Komarneni, S. (Eds.): Mullite. Weinheim 2005 [2] Bowen, N. L.; Greig, J. W.: The system aluminasilica. J. Amer. Ceram. Soc. 7 (1924) [4] 238– 254 [3] Schneider, H.; Okada, K.; Pask, J.: Mullite and mullite ceramics. Chichester 1994 [4] Aksay, I. A.; Dabbs, D. M.; Sarikaya, M.: Mullite for structural, electronic, and optical applications. J. Amer. Ceram. Soc. 74 (1991) [10] 2343–2358 [5] Ismail, M. G. M. U.; Nakai, Z.; Somiya, S.: Microstructure-mechanical properties of mullite prepared by the sol-gel method. J. Amer. Ceram. Soc. 70 (1987) [1] C7–C8 [6] Somiya, S.; Davis, R. F.; Pask, J. A.: Mullite and mullite matrix composites. Ceram. Trans. 6 (1990) [7] Marple, B. R.; Green, D. J.: Incorporation of mullite as a second phase into alumina by an infiltration technique. J. Amer. Ceram. Soc. 71 (1988) 471–473 [8] Marple, B. R.; Green, D. J.: Mullite processing, structure, and properties. Mullite-alumina particular composites by infiltration processing: Mechanical properties. J. Amer. Ceram. Soc. 74 (1991) [10] 2453–2459 [9] Taktak, S.; et al.: Fracture toughness of alumina- mullite composites produced by infiltration process. Key Engin. Mater. 264–268 (2004) 981–984 [10] Taktak, S.; Baspinar, S. M.: Wear and friction behaviour of alumina-mullite composite by sol-gel infiltration technique. Mater. and Design 26 (2005) 459–464 [11] www.nabaltec.de/download/produkte/SYMULOX_ M72-Z72_Datasheet_EN.PDF, 30. Jan. 2015. [12] www.nabaltec.de/download/produkte/ NABALOX_2xx_Datasheet_EN.pdf, 30. Jan. 2015 [13] Jander, G.; Blasius, E.: Lehrbuch der analytischen und präparativen anorganischen Chemie. 12th ed. Leipzig 1982, 70 [14] Atanga, V. K.; et al.: Alumina-mullite materials for refractory applications: microstructure, physical and finite element simulation of thermal shock behaviour. refractories WORLDFORUM 4 (2012) [1] 159–164
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