Oxidation and Volatilization of Silica-Formers in Water Vapor
Oxidation and Volatilization of Silica-Formers in Water Vapor
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DOI：
10.1111/j.1151-2916.2003.tb03459.x
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发表时间：
2013-08
期刊：
影响因子：
17.1
通讯作者：
E. Opila
中科院分区：
文献类型：
--
作者：
E. Opila
在高温下，SiC和Si3N4与水蒸气反应形成SiO2氧化皮。SiO2垢也与水蒸气反应形成挥发性Si（OH）4物质。这些同时发生的反应，一个形成SiO2和其他去除SiO2，描述了双线性动力学。最终达到稳定状态，其中这些反应以相同的速率发生。在达到稳定状态后，表面上的氧化物是恒定的厚度，并且下面的材料以线性速率发生衰退。稳态氧化物厚度、达到稳态的时间和稳态衰退速率可以用氧化和挥发反应的速率常数来描述。此外，氧化物厚度、达到稳定状态的时间和衰退速率也可以由描述含水蒸气环境的参数确定。因此，已经开发了地图，以显示这些稳态条件作为反应速率常数，压力和气体速度的函数。这些图谱可用于预测SiO2形成剂在含水蒸气环境（如燃烧环境）中的行为。最后，这些地图被用来探索SiC和Si3N4的双线性氧化模型的限制。
At high temperatures, SiC and Si3N4 react with water vapor to form a SiO2 scale. SiO2 scales also react with water vapor to form a volatile Si(OH)4 species. These simultaneous reactions, one forming SiO2 and the other removing SiO2, are described by paralinear kinetics. A steady state, in which these reactions occur at the same rate, is eventually achieved. After steady state is achieved, the oxide found on the surface is a constant thickness, and recession of the underlying material occurs at a linear rate. The steady-state oxide thickness, the time to achieve steady state, and the steady-state recession rate can be described in terms of the rate constants for the oxidation and volatilization reactions. In addition, the oxide thickness, the time to achieve steady state, and the recession rate also can be determined from parameters that describe a water-vapor-containing environment. Accordingly, maps have been developed to show these steady-state conditions as a function of reaction rate constants, pressure, and gas velocity. These maps can be used to predict the behavior of SiO2 formers in water-vapor-containing environments, such as combustion environments. Finally, these maps are used to explore the limits of the paralinear oxidation model for SiC and Si3N4.