Ag/Ni和Cu/Ni界面的分子动力学模拟

用分子动力学方法对金属界面在弯曲状态下的力学行为做了模拟计算．在自行设计的两种弯曲模型中，首先比较了Ａｇ／Ｎｉ在不形成界面、形成界面（错配比约为１５％）以及Ｃｕ／Ｎｉ形成界面（错配比约为３％）时在动态弯曲过程中的势能－应变曲线，应力－应变曲线，模量－应变曲线，通过比较得出的结论是：界面的存在影响很大，失配位错影响界面的性质，并且错配比不同界面的力学性质亦不相同．同时，对计算元胞的尺寸效应做了详细的讨论，给出了用于计算机模拟中比较适宜的计算元胞的尺寸．最后，利用圆弧弯曲模型将静态平移周期性边界条件应用于动态 关键词：

COMPUTER SIMULATION OF METAL INTERFACES

In this work, molecular dynamics (MD) method is applied to study the mechanical properties of Ag/Ni and Cu/Ni interface in two-dimensional models with atomic interactions represented by Lennard-Jones pair potentials. Because the investigated properties depend on the number of atoms in simulaton, and the run time and other resources are limited, we find the proper atom number of MD cell should be between 500-1000. Here, two types of boundary condition are used, one is rigid boundary, corresponding to three-point-bended inferface, the other is circular periodic condition, corresponding to circular-bended inferface. By using these boundary conditions, our MD calculations provide us a useful and consistent picture of the atomic scale processes which occur at Ag/Ni and Cu/Ni interfaces with different MD cell sizes, especially during bending interface processes. The results of our simulation are in good agreement with the macroscopic mechanical behavior, which verifies that the results of our work are correct to a large degree. We find that the properties of the interface are very different from that of single crystal, while the misfit of both lattices plays an important role in the interface properties of epitaxy bicrystal, and the interface structure greatly affects the properties of materials