Corrosion Behavior of Lu-Si-O System in Water Vapor

doi:10.3724/SP.J.1077.2010.00186

Abstract

Abstract:

Three kinds of lutetium silicates powders were prepared by solgel method, marked by Lu₂O₃·SiO₂, Lu₂O₃·2SiO₂ and Lu₂O₃·2.26SiO₂, respectively. Their corrosion behavior in water vapor was investigated in 50%H₂O-50%O₂ steam environment with a total pressure of 1.01×10⁵Pa at 1400℃. The specific weight change as a function of corrosion time was recorded. The phase evolution of lutetium silicate at different corrosion stages was observed by X-ray diffraction. The bonds of samples after corroded for different times were characterized by fourier transform infrared spectroscope(FTIR). The composition of corroded samples was analyzed by EDS. The results show that the main crystal phases of the as-prepared samples are Lu₂SiO₅+Lu₂Si₂O₇, Lu₂Si₂O₇+SiO₂ and Lu₂Si₂O₇+SiO₂, respectively. Lu₂SiO₅, instead of Lu₂Si₂O₇, reacts with Al₂O₃ to form garnet phase (Lu₃Al₅O₁₂) in the water vapor environment. This indicates that Lu₂Si₂O₇ exhibits more excellent chemical stability than Lu₂SiO₅.

Key words: Lu₂SiO₅, Lu₂Si₂O₇, environmental barrier coating (EBC), water vapor corrosion

CLC Number:

TB323

HONG Zhi-Liang,CHENG Lai-Fei,LU Lin-Jing,ZHANG Li-Tong,WANG Yi-Guang. Corrosion Behavior of Lu-Si-O System in Water Vapor[J]. Journal of Inorganic Materials, DOI: 10.3724/SP.J.1077.2010.00186.

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