中文摘要：

建立了原子力显微镜针尖切削单晶铜的三维分子动力学模型，采用嵌入原子势模拟工件原子之间的作用，采用Morse势模拟工件原子和刀具原子之间的作用。研究了工件材料的不同晶向和刀具切削方向、切削速度对工件亚表面变形层深度的影响。引入了原子势能变形判据，通过分析不同变形区域内原子的势能变化判断工件变形程度。观察了不同切削状态下亚表面原子势能的变化，发现工件材料晶向和切削方向对亚表面变形层深度有着显著影响。在切削速度为20～250m／s范围内，切削速度对亚表面变形层深度没有影响。

英文摘要：

Three-dimensional molecular dynamics simulations of nanometric cutting monocrystalline copper using atomic force microscope （AFM） pin tool are performed to investigate the effect of crystal orientation of work piece material, and cutting direction and cutting speed of tool on the depth of subsurface deformed layers. Embedded atom method （EAM） is used to simulate the interaction between workpiece atoms, and Morse potential is used to simulate the interaction between workpiece atoms and tool atoms. The potential energy variations of the atoms within the subsurface regions are obtained in the cutting process, a deformation criterion is presented to analyze the variations of subsurface atoms potential energy and determine subsurface atoms deformation behaviors. The simulation results reveal that the crystal orientation and cutting direction have a significant effect on the depth of subsurface deformed layers. Moreover, the depth of subsurface deformed layers is not affected by the cutting speed in the range of 20-250 m/s.