Influence of elliptical vibration on the behavior of silicon during nanocutting

Abstract

MDS (molecular dynamics simulation) was employed in this paper to study the nanometric cutting of monocrystalline silicon during the ultraprecision elliptical vibration–assisted cutting (UEVAC) process. The behavior of the workpiece during material removal by UEVAC has been studied, and the effects of different vibration frequencies, amplitude ratios, and phase differences on the deformation of the material have been carefully investigated. In these simulations, a long-range analytical bond order potential was used to model the interaction inside the silicon specimen. The results from the MDS showed that a smaller vibration frequency, higher amplitude ratio, or smaller phase difference generated less heat during cutting. Moreover, it was found that a smaller vibration frequency and a lower amplitude ratio lead to a larger material removal rate, and that a higher amplitude ratio could reduce the thickness of the subsurface damage and von Mises stress of the workpiece. However, the results showed that a smaller vibration frequency increased the overall magnitude of the resultant force. It was also found that the decrease of the amplitude ratios caused an increase in the average normal forces and the resultant forces. In addition, the use of a cutting amplitude ratio of 10/3 reduced the cutting force and tended to machine the workpiece in a more ductile mode due to there being less crack propagation. Besides, a phase difference of 120° improved the material removal rate, but a phase difference of 60° reduced the cutting force.