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摘要轧制复合材料与常规材料相比，具有许多优异的性能。Cu-Al复合材料同时具有铜的导电、导热率高和铝的质地轻、价格低廉等优点，此在航空、汽车等领域有广泛的应用前景，因此Cu-Al双金属轧制复合过程的原子方面的研究具有重要意义。本文即运用分子动力学方法，结合角度关联（ADP）势函数对Cu-Al轧制复合过程进行原子模拟。分别对系统进行压缩和拉伸处理，研究其过程中材料内部原子运动的细节，及材料中的应力变化和结构畸变等行为，给出原子级别上的材料塑性变形和原子扩散的直观图景，得出以下结论：（1）系统的晶界能随着温度的升高小幅度线性增加（2）压缩过程中靠近界面处的Al、Cu晶格随着扩散的进行由完整结构变为无定型结构；界面层的扩散厚度随扩散时间增加而增加；大形变时温度不是影响扩散层厚度的关键因素（3）拉伸过程体系经历了弹性变形和塑性变形阶段.28240
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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