( 1. 湖南冶金職業(yè)技術(shù)學(xué)院 冶金系, 株洲 412000;
2. 中南大學(xué) 冶金科學(xué)與工程學(xué)院, 長沙 410083)
摘 要: 用熱重法測定了鋅蒸氣在不同溫度和氣氛下的氧化動力學(xué)曲線，用掃描電鏡觀察分析產(chǎn)物的結(jié)晶形貌。 結(jié)果表明： 氧化動力學(xué)遵守直線規(guī)律時， 產(chǎn)物的結(jié)晶形貌是無定形、 顆粒狀和單針狀； 氧化動力學(xué)曲線為拋物線規(guī)律時， 產(chǎn)物的結(jié)晶形貌是四針狀和多針狀。氧化動力學(xué)轉(zhuǎn)變規(guī)律的原因是鋅蒸氣中存在超細(xì)鋅微粒與氣態(tài)鋅原子的動態(tài)平衡。 應(yīng)用動力學(xué)理論和上述結(jié)果推斷了相關(guān)條件下的動力學(xué)機理函數(shù)和動力學(xué)常數(shù)， 研究了鋅微粒的氧化過程并求出了鋅原子通過氧化膜層的擴散系數(shù)。
關(guān)鍵字: 鋅蒸氣; 鋅微粒; 氧化動力學(xué); 動力學(xué)機理函數(shù); 氧化鋅結(jié)晶形貌
YANG Sheng-hai2, TANG Mo-tang2
（ 1. Department of Metallurgy, Hunan Metallurgical Institute of Professional Technology, Zhuzhou 412000, China;
2. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract: The kinetics of oxidizing zinc vapor in different atmosphere at elevated temperature was determined by thermalgravity apparatus and the morphologies of the oxidation products were examined by scanning electron microscopy. The results show that the products morphologies are amorphous, granular, needle-like when the kinetics advances linearly and the products of tetrapod and multipod-like ZnO appear as the kinetics proceeds parabolically. The change of the oxidation kinetics law is caused by tiny zinc particles formed in zinc vapor. The relative kinetic model functions and kinetics parameters of the title reaction were deduced from kinetic theories and the experimental data. The oxidation mechanism of the tiny zinc particles were investigated and the diffusion coefficient of Zn atoms through the oxidation scale were also deduced.
Key words: zinc vapor; zinc particles; oxidation kinetics; kinetic model functions; ZnO morphologies
