Large scale molecular dynamics study of nanometric machining of copper
Large scale molecular dynamics study of nanometric machining of copper
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DOI：
10.1016/j.commatsci.2007.04.008
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发表时间：
2007-12-01
影响因子：
3.3
通讯作者：
Lee, H. P.
中科院分区：
文献类型：
--
作者：
Pei, Q. X.;Lu, C.;Lee, H. P.
纳米加工是指在纳米尺度下对材料进行加工，分子动力学（MD）模拟是研究纳米加工机理和加工过程的重要工具。在这项研究中，一系列大规模的MD模拟与模型尺寸超过四百万个原子已经进行了研究的纳米加工铜。对切削过程中有限温度下的位错进行了识别，研究了位错的形核和运动规律。研究了切削深度、切削速度、晶体取向和切削方向对材料变形、晶格缺陷和切削力的影响。仿真结果表明，切削深度越小，工件塑性变形越小，位错越少，加工表面越光滑。研究发现，随着切削深度的减小，比切削力迅速增大，表明纳米加工中存在“尺寸效应”。据观察，更高的切割速度导致更多的晶格缺陷在切割区域和更高的切割力。结果表明，晶体取向和切削方向对材料变形、位错运动和切削力有很大影响。(c)2007 Elsevier B.V.保留所有权利。
Nanometric machining involves removal of materials at the order of a few nanometers or less. At such a small length scale, molecular dynamics (MD) simulation is an important tool in studying the nanometric machining mechanism and process. In this study, a series of large scale MD simulations with the model size of more than four-million atoms have been performed to study the nanometric machining of copper. The dislocations at finite temperature during the cutting processes are identified and their nucleation and movement are studied. The effects of cutting depth, cutting speed, crystal orientation and cutting direction on the material deformation, lattice defects and cutting forces are investigated. The simulation results show that a smaller cutting depth results in less plastic deformation and fewer dislocations in the workpiece and thus result in a smoother machined surface. It is found that as the cutting depth decreases, the specific cutting force increases rapidly, which shows that the "size effect" exists in nanometric machining. It is observed that a higher cutting speed results in more lattice defects at the cutting region and higher cutting forces. It is revealed that the crystal orientation and cutting direction have a strong effect on material deformation, dislocation movement and cutting forces. (c) 2007 Elsevier B.V. All rights reserved.