Cu-Al双金属轧制复合过程的原子模拟
关键字 分子动力学 ADP势函数 扩散焊 轧制复合
毕业论文设计说明书外文摘要
Title Atomic simulation on rolling process of aluminum-copper composite structures
Abstract
compared to conventional materials ,rolling composites has many excellent properties.The aluminum-copper composite structures have many advantages，such as high conductivity, high thermal conductivity, light texture, cheap ,and etc, it has a widely application in the filed of aerospace and automotive ，so the study of the atomic simulation on rolling process of Al-Cu composite structures is very important. In this paper, the molecular dynamics (MD) technique was employed to simulate the rolling process of aluminum-copper composite structures in combine with the angular-dependent potential (ADP). Compression and tension was done on the rolling process , we considered the details of atomic motion and the behaviors of stress change and structural aberrations within the material ,then give intuitive pictures of atomic diffusion and plastic deformation of materials in the atomic scale. From the simulation results，the following results are obtained ：
(1)Grain boundary energy of system is increase linearly with the temperature rises.
(2) In the process of compression, the complete structure of Al and Cu lattice near the interface becomes to amorphous structure; longer diffusion time yielding larger thicknesses; temperature is not the key factors affect the thicknesses of large deformation .(3) The system has experienced elastic deformation and plastic deformation during stretching process.
Keywords Molecular dynamics ADP potential Diffusion bonding Rolling process
目 次
1 引言 2
1.1 扩散焊与轧制复合的基本介绍 3
1.2 分子动力学(MD)中关于界面扩散的研究进展 4
1.3 本文的研究内容及意义 5
2 分子动力学方法 5
2.1 发展历程 6
2.2 基本概念 6
2.3 计算方法 6
2.3.1 蛙跳算法(leap frog methods) 7
2.3.2 预测-校正法 8
2.3.3 Velocity-Verlet算法 9
2.4其他条件的设定 9
2.4.1 边界条件的设定 9
2.4.2 时间步长与初始速度的选取 10
3 势函数的选取 11
3.1 嵌入原子（EAM）势[21] 12
3.2 修正的嵌入原子势（MEAM）势[22] 12
3.3 Finnis- Sinclair 势[25] 13