(1. 中南工业大学 冶金科学与工程系, 长沙 410083;
2. 中南工业大学 粉末冶金研究所, 长沙 410083;
3. 中国长城铝业公司 氧化铝厂, 郑州 450041)
摘 要: 从热力学和动力学角度研究了亚微米级SiC粉体的氧化过程, 结果表明: 当温度低于800 ℃, 亚微米级的SiC粉体很难在空气中氧化; 但在较高温度下(900~1 200 ℃)极易氧化, 且服从抛物线速度方程, 受氧气通过SiO2氧化膜的内扩散控制, 反应的平均表观活化能为143.4 kJ/mol。
关键字: 亚微米级SiC粉体; 氧化; 热力学;动力学
(1. Department of Metallurgical Science and Engineering, Central South University of Technology, Changsha 410083, P.R.China;
2. Research Institute of Powder Metallurgy,Central South University of Technology, Changsha 410083, P.R.China;
3. Alumina Plant, China Great Wall Aluminium Coperation, Zhengzhou 450041, P.R.China)
Abstract:The oxidation of silicon carbide was investigated from both thermodynamic and kinetics aspects. The results indicated that the oxidation of silicon carbide is very easy to take place in the oxygen atmosphere at high temperature. It waspostulated that the inward diffusion of oxygen through the growing silicon dioxidelayer formed on the surface of silicon carbide particles during oxidation period, is the ratedetermining step. The apparent activation energy inthis process was also obtained as 143.4 kJ/mol over the temperature range from 1 173.15 K to 1 473.15 K.
Key words: submicrometer SiC powder; oxidation; thermodynamics; kinetics