Fe/Ni多层薄膜尺寸效应的分子动力学模拟

The Fe/Ni Multilayers Size Effects Simulation by Molecular Dynamics

摘要:

本文采用分子动力学方法对BCC/FCC对接结构的Fe/Ni多层薄膜系统进行了模拟研究，通过改变薄膜的单层厚度来研究薄膜的尺寸效应，薄膜单层厚度的变化范围在6 nm~26 nm之间。模拟结果显示，随着Fe/Ni薄膜单层厚度的减小，屈服应力呈增加趋势，符合经典的Hall-Petch关系；当单层厚度减小到某一临界尺寸(10.6 nm~15.18 nm)后，Fe/Ni薄膜的屈服应力不再增加，在一定的范围内波动，当薄膜单层厚度进一步减小时，屈服应力呈减小的趋势，显示出反Hall-Petch关系。

Abstract: In this article, molecular dynamics simulations were carried out to study the mechanical properties of fcc-bcc Ni-Fe Multilayer. The size effects were studied by changing the individual layer thickness, which varies from 6 to 26 nanometers. The simulation results show that the yield stress increased with the decreasing of thickness of single layer, which accords with the classic Hall-Petch relation. When the individual layer thickness decreases to a critical size (10.6 nm - 15.18 nm), the yield stress of Fe/Ni film does not increase again and shows a certain range of fluctuation. When the thickness of single-layer further reduced, the yield stress showed a trend of decreasing, which accords with the reverse Hall-Petch relation.