(1. 中南工業(yè)大學(xué) 冶金科學(xué)與工程系, 長(zhǎng)沙 410083;
2. 中南工業(yè)大學(xué) 粉末冶金研究所, 長(zhǎng)沙 410083;
3. 中國(guó)長(zhǎng)城鋁業(yè)公司 氧化鋁廠, 鄭州 450041)
摘 要: 從熱力學(xué)和動(dòng)力學(xué)角度研究了亞微米級(jí)SiC粉體的氧化過(guò)程, 結(jié)果表明: 當(dāng)溫度低于800 ℃, 亞微米級(jí)的SiC粉體很難在空氣中氧化; 但在較高溫度下(900~1 200 ℃)極易氧化, 且服從拋物線速度方程, 受氧氣通過(guò)SiO2氧化膜的內(nèi)擴(kuò)散控制, 反應(yīng)的平均表觀活化能為143.4 kJ/mol。
關(guān)鍵字: 亞微米級(jí)SiC粉體; 氧化; 熱力學(xué);動(dòng)力學(xué)
(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


