单晶铜AFM加工过程的分子动力学模拟

Molecular Dynamics Simulation of Copper Processing Using AFM Pin Tool

建立了AFM针尖切削单晶铜的分子动力学模型。分别采用对势Morse势和多体势EAM势计算工件原子之间的相互作用,研究了不同势能函数对模拟结果的影响。发现两种不同势能函数作用下切屑和加工表面的形成的差别很小,但是用Morse势时系统的势能和牛顿层的温度比用EAM势时要大。用EAM势计算工件原子之间的相互作用,分析了不同切削深度下系统势能、工件单个原子势能的变化,发现随着切削深度的增加,系统势能增长的斜率增加,单个工件原子势能突变的梯度减小。

Molecular dynamics （MD） simulation was employed to study the nanometric processing of single crystal copper by an AFM pin tool. In our approach, the two-body Morse potential and the many-body EAM potential were used for the atoms interaction in the copper workpiece to study the effect of different potentials on the simulation results. It is found that there is no obvious difference in the chip formation and the machined surface. But the Morse potential results in bigger system potential energy and higher temperature of the Newtonian atoms. EAM potential was carried out to simulate the atoms interaction in the single crystal copper workpiece. The diversifications of system potential energy and workpiece single atom potential energy at different cutting depths were both analyzed. It is showed that when the cutting depth increases, the slope of system potential energy variation increases, the jump＇s grads of workpiece＇s single atom potential decreases.