采用分子动力学的方法研究了Al-Ag合金粉末在氧化气氛进行热处理的物相转变与扩散行为,着重对物相扩散速率、转变温度、Ag-Al2O3物相转变过程进行了研究。结果表明：O原子与Al原子的相互作用为Ag原子的扩散提供动力,Ag的析出与Al2O3致密氧化膜的形成相互冲突,在600 K氧化气氛下合金粉末中Ag的析出速率大,内部形成Ag2Al相。实验结果验证了模型设计与计算结果的合理性,表明通过控制反应温度、Al2O3致密氧化膜的形成和Ag的短路径扩散能够控制Ag在纳米尺度内。
In order to investigate the diffusion and transition mechanism for Ag in Ag-Al supersaturated solid under oxygen atmosphere,the diffusion rate,temperature and process for Ag-Al-O phase transition were calculated by the molecular dynamics simulation.The calculated results show that there are conflict between precipitation of Ag and formation of compact alumina film during oxidation process,Ag precipitates quickly at 600 K in oxygen atmosphere,associated with the formation of the Ag2Al phase in Al-Ag solution.The model and calculation result were proved to be reasonable through experiment,Ag in nano scale could be controlled through the short path diffusion of Ag and formation of compact alumina film under reaction temperature.
参考文献
| [1] | He H, Dong X P, Yang M. Catalytic inactivation of SARS coronavirus escherichia coli and yeast on solid surface [J]. Catal Commun, 2004, 5(3): 170-175. |
| [2] | 闫李珠, 陈雪梅, 贺泓. Al2O3负载Ag催化剂的杀菌作用[J]. 催化学报, 2005, 26(12): 1122-1126. |
| [3] | N Raveendran Shiju, Vadim V Guliants. Recent developments in catalysis using nano-structured materials [J]. Applied Catalysis A, 2009, 3(6): 1-17. |
| [4] | 毛从文, 蒋新. 吸附法原位制备Ag/SiO2纳米复合材料[J]. 复合材料学报, 2006, 23(4): 88-94. |
| [5] | Breen J P, Burch R, Hardacre C. An investigation of the thermal stability and sulphur tolerance of Ag/γ-Al2O3 catalysts for the SCR of NOx with hydrocarbons and hydrogen [J]. Appl Catal B, 2007, 36(70): 104-109. |
| [6] | Liu Zhiming, Li Junhua, Abu S M. Knowledge and know-how in improving the sulfur tolerance of NOx catalysts [J]. Catalysis Today, 2010, 15(3): 95-102. |
| [7] | 杨晓峰, 董相廷, 周艳慧. 贵金属核壳纳米粒子最新研究进展[J]. 稀有金属材料与工程, 2009, 38(2): 368-372. |
| [8] | Rappe A K, Casewit C J, UFF K S. A full periodic table force field for molecular mechanics and molecular dynamics simulations [J]. J Am Chem Soc, 1992, 11(4): 1024-1035. |
| [9] | Bouanich J P. Site-site Lennard-Jones potential parameters for N2, O2, H2, CO and CO2 [J]. Journal of Quantitative Spectroscopy and Radiative Transfer, 1992, 47(4): 243-250. |
| [10] | Heinz H, Vaia R A, Farmer B L. Accurate simulation of surfaces and interfaces of face-centered cubic metals using 12-6 and 9-6 Lennard-Jones potentials [J]. J Phys Chem C, 2008, 112(44): 17281-17290. |
| [11] | Timpel Dirk, Scheerschmidt Kurt, Garofalini Stephen H. Silver clustering in sodium silicate glasses--A molecular dynamics study [J]. Journal of Non-Crystalline Solids, 1997, 22(2): 187-198. |
| [12] | Massobrio C, Pontilis V, Martin G. Molecular-dynamics study of amorphization by introduction of chemical disorder in crystalline NiZr2[J]. Phys Rev B, 1990, 41(15): 10486-10497. |
| [13] | Cleri F, Rosato V. Tight-binding potentials for transition metals and alloys [J]. Phys Rev B, 1993, 48(1): 22-33. |
| [14] | Papanicolaou N I, Chamati H, Evangelakis G A. Second-moment interatomic potential for Al, Ni and Ni-Al alloys and molecular dynamics application [J]. Computational Materials Science, 2003, 27(2), 191-198. |
| [15] | Junko Habasaki, Isao Okada. Molecular dynamics simulation of alkali silicates based on the quantum mechanical potential surfaces [J]. Molecular Simulation, 1992, 9(5): 319-326. |
| [16] | Campbell Timothy, Kalia Rajiv K, Nakano Aiichiro. Dynamics of oxidation of aluminum nanoclusters using variable charge molecular-dynamics simulations on parallel computers [J]. Phys Rev Lett, 1999, 82(24): 4866-4869. |
| [17] | 丁丽颖, 耿春宇, 赵月红. 甲烷水合物分解及自保护效应的分子动力学模拟[J]. 中国科学B辑: 化学, 2008, 38(2): 161-169. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%