Study on Nanometric Machining Mechanism of Monocrystalline Silicon by Molecular Dynamics

A three-dimensional model of molecular dynamics (MD) was employed to study the nanometric cutting mechanism of monocrystalline silicon. The model included the utilization of the Morse potential function to simulate the interatomic force between the workpiece and the tool, and the Tersoff potential function between silicon atoms. Amorphous phase transformation and chip volume change are observed by analyses of the snapshots of the MD simulation of the nanometric cutting process, energy and cutting forces. Dislocations and elastic recovery in the deformed region around the tool do not appear. Cutting forces initiate the amorphous phase transformation, and thrust forces play an important role in driving the further transformation development. Nanometric cutting mechanism of monocrystalline silicon is not the plastic deformation involving the generation and propagation of dislocations, but deformation via amorphous phase transformation.