Variation of the oxidation rate of silicon carbide with water-vapor pressure
Variation of the oxidation rate of silicon carbide with water-vapor pressure
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DOI：
10.1111/j.1151-2916.1999.tb01810.x
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发表时间：
1999-03-01
影响因子：
3.9
通讯作者：
Opila, EJ
中科院分区：
文献类型：
--
作者：
Opila, EJ
化学气相沉积碳化硅（CVD SiC）在1000 -1400 ℃的温度下在具有10-90体积%水蒸气的组成的H2O/O-2气体混合物中在1大气压的总压力下氧化。在1100 ℃的温度下在H2O/氩气混合物中进行另外的实验。实验的目的是尽量减少杂质和挥发性的影响，使只有内在的水蒸气的影响进行了观察。随着水蒸气含量的增加，氧化动力学增加。在10-90体积%水蒸气（余量为氧气）范围内的抛物线氧化速率比在1200 -1400摄氏度的温度下在干燥氧气中观察到的速率高大约一个数量级。幂律依赖的抛物线氧化速率在所有温度下的水蒸气分压的研究表明，分子物种是不是唯一的限速氧化剂。扩散活化能的测定是复杂的氧化机制和氧化物的规模形态与水蒸气分压和温度的变化。
Chemically vapor deposited silicon carbide (CVD SiC) was oxidized at temperatures of 1000 degrees-1400 degrees C in H2O/O-2 gas mixtures with compositions of 10-90 vol% water vapor at a total pressure of 1 atm. Additional experiments were conducted in H2O/argon mixtures at a temperature of 1100 degrees C. Experiments were designed to minimize impurity and volatility effects, so that only intrinsic water-vapor effects were observed. The oxidation kinetics increased as the water-vapor content increased. The parabolic oxidation rates in the range of 10-90 vol% water vapor (the balance being oxygen) were approximately one order of magnitude higher than the rates that were observed in dry oxygen for temperatures of 1200 degrees-1400 degrees C. The power-law dependence of the parabolic oxidation rate on the partial pressure of water vapor at all temperatures of the study indicated that the molecular species was not the sole rate-limiting oxidant. The determination of an activation energy for diffusion was complicated by variations in the oxidation mechanism and oxide-scale morphology with the partial pressure of water vapor and the temperature.