Molecular Dynamics Investigation of Cutting Force in Nanometric Cutting of Monocrystalline Silicon

Abstract

Problem statement: Ultra-precision machining of monocrystalline silicon has become tremendously important in microelectronic, micromechanical and optical element manufacturing and the mechanism of nanometric cutting monocrystalline silicon has been a focused research topic. Molecular Dynamics (MD) simulation is developed as an effective way for studying the material removal process at nanometric scale. Approach: Molecular Dynamics (MD) simulation of nanometric cutting is conducted on monocrystalline silicon with three dimensional diamond tool of 0° rake angle to investigate the cutting force. The cutting process is explicitly described by the combination of Morse and Tersoff potential. Nanometric cutting process is explained using the mechanism of tool extrusion induced lattice slip and distortion. Results: Cutting force vibration phenomenon is investigated in detail. Simulations on different tool cutting edges are carried out with various cutting depth to study the cutting force variation. The threshold cutting depth for chip formation is given. Conclusion: It is noted that cutting force vibration which is the main reason for tool wear and surface fracture is the result of tool extrusion and material deformation. The cutting force curves are distinct from the threshold cutting depth of chip formation and cutting forces decrease as the cutting edge value increase when cutting with same cutting depth.