材料科学
热重分析
润湿
氧化物
陶瓷基复合材料
复合材料
陶瓷
扫描电子显微镜
氧气
挥发
纤维
化学工程
冶金
工程类
物理
有机化学
核物理学
化学
作者
Kaitlin Detwiler,Elizabeth J. Opila
标识
DOI:10.1016/j.jeurceramsoc.2022.04.003
摘要
The oxidation behavior of SiC/BN/SiC ceramic matrix composites (CMCs) was evaluated from 400° to 800 °C in 100% O2 and 50% H2O/50% O2 gas mixtures. Thermogravimetric analysis (TGA) was utilized to measure weight change during controlled environment exposures at elevated temperatures for 1 and 50 hours. Oxidized CMCs and their oxides were studied post-exposure with scanning electron microscopy and energy dispersive spectroscopy. The oxidation onset and composition transition temperatures were evaluated. Key observations include oxide composition, oxide wetting, oxygen solubility in Hi-Nicalon SiC fibers and BN fiber coating oxidation and volatility behavior as a function of temperature. Degradation in wet environments at 600 °C was most extensive due to the formation of a non-wetting, non-protective surface oxide, allowing oxidant access to the BN fiber coatings followed by oxidation and volatilization. Implications of the CMC oxidation behavior are discussed for CMCs in service.
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