单晶硅和单晶铝纳米切削过程比较

Comparison of nanometric cutting processes for monocrystalline silicon and aluminum

采用分子动力学模拟方法进行了单晶硅和单晶铝纳米切削过程的比较研究,硅原子间相互作用力采用Tersoff势计算,铝原子间和工件与刀具原子间相互作用力采用Morse势计算。通过对切削过程中切屑和加工表面、能量和切削力的分析,发现硅发生非晶态相位变换和切屑体积改变,但没有位错和弹性恢复产生;而铝发生的现象却与硅相反。

A three-dimensional model of molecular dynamics (MD) was employed to study the nanometric cutting processes for monocrystalline silicon and aluminum. The model included the utilization of the Tersoff potential function to simulate the interatomic force between silicon atoms, and the Morse potential function between the workpiece and a tool and between aluminum atoms. Amorphous phase transformation, chip volume change, no dislocations and no elastic recovery in silicon were observed by analysis of chip and machined surface, energy and cutting forces, but these were not so for aluminum. Nanometric cutting mechanism of mono-crystalline aluminum is the plastic deformation involving the generation and propagation of dislocations, and silicon deformation via amorphous phase transformation.