金属高Miller指数表面能的分子动力学研究

MOLECULAR DYNAMICS SIMULATION OF THE SURFACE ENERGIES OF HIGH-INDEX SURFACES IN METALS

利用嵌入原子型原子间相互作用势的分子动力学,计算了金属Al,CU,Ni位于两个晶带上([001]晶带和[110]晶带)一系列高Miller指数面的表面能.推广了基于表面结构单元模型的经验公式.计算结果表明,利用本文推广的经验公式可根据几个低Miller指数面的表面能估计出高Miller指数面的表面能和表面结构特征.最密排面的表面能最低;最密排面(111)和次密排面(110),(100)的表面能分别是表面能值随晶向角度θ变化曲线上的极小值;理论模拟结果、公式计算结果和已有的实验数据三者符合得较好.

Interatomic potentials of the embedded atom (EAM) type and molecular dynamics simulation are used to calculate the surface energies of the high-index surfaces containing the [001] or [110] zone axis in Al, Cu and Ni. Two empirical formulas are developed based on structural unit model for high-index surfaces. The calculation result shows these formulas can be used to give an estimation of the energies of the high-index surfaces. The closest packed surfaces have the lowest surface energy and the surface energies of the closest surface (111) surface and the next closest surfaces (110) and (100) surfaces are the extremum on the curve of surface energy versus orientation angle. Both the theoretical simulation results and the empirical formula calculation results consist with the available experiment data.