The Effect of Interatomic Potential Function on Nanometric Machining of Single Crystal Silicon

Nanometric machining process is an advanced method for producing brittle silicon workpiece with nano-level surface finish. With the aid of molecular dynamics simulation, valuable details of machining mechanism could be obtained. Choosing the appropriate potential function is the main parameter in determining the results of this simulation. In this paper, the combination of the three potential functions of Morse, Tersoff, and Stillinger-Weber is used to define interatomic interactions. The machining mechanism, workpiece temperature, cutting forces, systems’ energy as well as subsurface damages were studied to compare these potential functions. The results exhibit that using the combination of the Morse and Tersoff potential function would change the machining mechanism to brittle mode and reduce the system energy by as much as 7.3%. It is also found that the interaction between tool and workpiece has a greater influence on the determination of the workpiece temperature and machining forces.