Pei Q X, Lu C, Lee H P, Zhang Y W
Institute of High Performance Computing, 1 Fusionopolis Way, Singapore, 138632 Singapore.
Nanoscale Res Lett. 2009 Feb 18;4(5):444-451. doi: 10.1007/s11671-009-9268-z.
Nanometric cutting involves materials removal and deformation evolution in the surface at nanometer scale. At this length scale, atomistic simulation is a very useful tool to study the cutting process. In this study, large-scale molecular dynamics (MD) simulations with the model size up to 10 millions atoms have been performed to study three-dimensional nanometric cutting of copper. The EAM potential and Morse potential are used, respectively, to compute the interaction between workpiece atoms and the interactions between workpiece atoms and tool atoms. The material behavior, surface and subsurface deformation, dislocation movement, and cutting forces during the cutting processes are studied. We show that the MD simulation model of nanometric cutting has to be large enough to eliminate the boundary effect. Moreover, the cutting speed and the cutting depth have to be considered in determining a suitable model size for the MD simulations. We have observed that the nanometric cutting process is accompanied with complex material deformation, dislocation formation, and movement. We find that as the cutting depth decreases, the tangential cutting force decreases faster than the normal cutting force. The simulation results reveal that as the cutting depth decreases, the specific cutting force increases, i.e., "size effect" exists in nanometric cutting.
纳米切削涉及材料在纳米尺度表面的去除和变形演变。在这个长度尺度下，原子模拟是研究切削过程的非常有用的工具。在本研究中，已进行了模型尺寸达1000万个原子的大规模分子动力学（MD）模拟，以研究铜的三维纳米切削。分别使用嵌入原子法（EAM）势和莫尔斯势来计算工件原子之间的相互作用以及工件原子与刀具原子之间的相互作用。研究了切削过程中的材料行为、表面和亚表面变形、位错运动以及切削力。我们表明，纳米切削的MD模拟模型必须足够大以消除边界效应。此外，在确定用于MD模拟的合适模型尺寸时必须考虑切削速度和切削深度。我们观察到纳米切削过程伴随着复杂的材料变形、位错形成和运动。我们发现随着切削深度减小，切向切削力比法向切削力下降得更快。模拟结果表明，随着切削深度减小，比切削力增加，即纳米切削中存在“尺寸效应”。
