腐蚀介质在金属表面扩散行为的分子动力学研究  

Molecular Dynamics Study of Corrosive Medium Diffusion in Metal Surface

作　　者：王超明[1] 胡军[1] 郑茂盛[1] 余历军[1] 

机构地区：[1]西北大学化工学院

出　　处：《化工机械》2015年第5期658-661,705,共5页Chemical Engineering & Machinery

基　　金：国家自然科学基金资助项目(51301132);高等学校博士点基金资助项目(20136101120009);中国博士后基金资助项目(2014M550507);陕西省教育厅专项基金资助项目(14JK1751)

摘　　要：采用分子动力学方法,研究了3种介质粒子(Cl-、OH-、H2O)与两种金属氧化膜界面Fe2O3(00-1)、Cr2O3(0 0-1)的交互作用能和它们在这些氧化膜表面的扩散过程。计算结果表明:Cl-与Fe2O3和Cr2O3的交互作用能分别为-8 875、-9 227kcal/mol,而OH-和H2O与Fe2O3的交互能仅仅为-225、-258kcal/mol。Cl-、OH-和H2O在Cr2O3中的扩散系数分别为6×10-5cm2/s、8×10-5cm2/s和3×10-6cm2/s。交互作用能说明:Cl-与金属氧化膜的作用性更强,OH-和H2O与金属氧化膜的作用性相对弱一点,因此交互作用能可以是评价粒子腐蚀性的重要依据之一;扩散系数也是评价粒子对金属腐蚀性的一个指标,但是评价单个粒子对金属的腐蚀性能时不仅取决于其自身的扩散系数,而且还应该与所在溶剂的分子在金属氧化物表面的扩散系数有关。Through molecular dynamics simulation, the three particles＇ （Cl- , OH-and H=O） respective interaction with two types of metal oxide membrane interface [ Fe2O3 （0 0 - 1 ）, Cr2O3 （0 0 - 1 ） ] were reinvestigated, including the particles＇ diffusion in the metal oxide membrane interface. The results indicate that the C;- s interaction with Fe203 and Cr203 are- 8 875kcal/mol and- 9 227kcal/mol respectively; and the interaction energies between OH- , H=O and Fe203 stay at -225kcal/mol and- 258kcal/mol respectively; the Cl- , OH - and H2O＇ s diffusion coefficients in Cr2O3 are 6× 10 -5cm2/s, 8× 10 -5cm2/s and 3 × 10-6cm2/srespectively. The above calculation indicates that the Cl- ＇ s interaction energy with metal oxide film becomes significantly greater than OH- and H2O＇s with metal oxide film; the interaction energy can be one of the important parameters to evaluate the corrosive characteristics of media particles and the diffusion coefficient is another indicator to evaluate corrosive characteristics of media particles; judging the corrosive characteristics of media particles depends on its own diffusion coefficient and that of relevant solvent molecules in the interface of metal oxide.

关 键 词：分子动力学 交互能量 扩散系数 氧化膜 

分 类 号：TQ050.9[化学工程]