Journal of Inorganic Materials >
Corrosion Behavior of AlNbO4/Mullite Composite as Environmental Barrier Coating in Water Vapor Environment
(State Key Lab of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China)
Received date: 2009-10-22
Revised date: 2009-12-09
Online published: 2010-04-27
AlNbO4/mullite composite environmental barrier coating (EBC) with 5mol% AlNbO4 content was prepared on Si3N4 substrate by atmospheric plasma spraying (APS). There was evidence that the weight loss rate of Si3N4 substrate coated by AlNbO4/mullite composite was less than that of Si3N4 substrate coated by mullite during the first 50h corrosion test. The improved protective capacity of AlNbO4/mullite composite coating was ascribed to the formation of glassy AlNbO4 top surface. After 100h corrosion test, the AlNbO4/mullite coating was still stable and no further corroded cavities were observed. However, slight delamination of the coating and a faster weight loss rate was observed after long time corrosion due to the coefficient of thermal expansion (CTE) mismatch between AlNbO4/mullite composite and Si3N4 substrate.
Key words： mullite; AlNbO4; environmental barrier coating; water vapor corrosion
WU Jiang , LIN Hong , LI Jian-Bao , LI Jun-Feng . Corrosion Behavior of AlNbO4/Mullite Composite as Environmental Barrier Coating in Water Vapor Environment[J]. Journal of Inorganic Materials, 2010 , 25(4) : 445 -448 . DOI: 10.3724/SP.J.1077.2010.09725
［1］Lee K N. Current status of enverimental barrier coatings for Sibased ceramics. Surf. Coat. Tech., 2000, 133-134: 1-7.
［2］Sarin P, Yong W, Haggerty R P, et al. Effect of transition-metal-ion on high temperature expansion of 3:2 mullite-An in situ, high temperature, synchrotron diffraction study. J. Eur. Ceram. Soc., 2008, 28(2): 353-365.
［3］Maier N, Nickel K G, Rixecker G. High temperature water vapor corrosion of rare earth disilicates (Y,Yb,Lu)2Si2O7 in the presence of Al(OH)3 impurities. J. Eur. Ceram. Soc., 2007, 27(7): 2705-2713.
［4］Schmücker M, Mechnich P, Zaefferer S, et al. Water vapor corrosion of mullite: single crystals versus polycrystalline ceramics. J. Eur. Ceram. Soc., 2008, 28(2): 425-429.
［5］Ramachandra C, Lee K N, Tewari S N. Durability of TBCs with a surface environmental barrier layer under thermal cycling in air and molten salt. Surf. Coat. Tech., 2003, 172(2/3): 150-157.
［6］Bai J, Maute K, Shah S R, et al. Mechanical design for accommodating thermal expansion mismatch in multilayer coatings for environmental protection at ultrahigh temperature. J. Am. Ceram. Soc., 2007, 90(1): 170-176.
［7］Lee K N, Fox D S, Bansal N P. Rare earth silicate environmental barrier coatings for anSiC/SiC composites and Si3N4 ceramics. J. Eur. Ceram. Soc., 2005, 25(10): 1705-1715.
［8］Ueno S, Ohji T, Lin H T. Corrosion and recession of mullite in water vapor environment. J. Eur. Ceram. Soc., 2008, 28(2): 431-435.
［9］Fritsch M, Klemm H, Herrmann M, et al. Corrosion of selected ceramic materials in hot gas environment. J. Eur. Ceram. Soc., 2006, 26(16): 3557-3565.
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