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Effects of In-Situ-Formed 9Al2O3·2B2O3 on the Corrosion Resistance of Al2O3-Based Porous Ceramic in Molten Aluminum
R. Xiang, Y. Li, D. Xiang, N. Li, S. Li, S. Sang
The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, PR China
received July 23, 2015, received in revised form October 23, 2015, accepted November 11, 2015
Vol. 7, No. 1, Pages 113-118 DOI: 10.4416/JCST2015-00037
Abstract
White fused alumina (WFA), α-Al2O3 powder, aluminum hydroxide powder and pseudoboehmite powder (PB) are each mixed with boric acid according to the stoichiometric ratio of 9Al2O3·2B2O3 in order to study the formation process. For the corrosion experiment, Al2O3-based porous ceramic with and without the addition of boric acid is prepared and soaked in molten aluminum for 48 h at 870 °C. The results show that the synthesis temperature of 9Al2O3·2B2O3 is 1000 °C, except for the mixture of PB and boric acid for which the synthesis temperature is 900 °C. The corrosion resistance of the samples with the addition of boric acid in molten aluminum is improved because of the generation of 9Al2O3·2B2O3 around the pores.
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Keywords
Porous ceramic, in-situ synthesization, 9Al2O3·2B2O3, molten aluminum, corrosion resistance
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