Prediction of cutting forces in the micro-machining of silicon using a “hybrid molecular dynamic-finite element analysis” force model

The study and development of micro-machining technology has been an area of ongoing focus for numerous researchers. Interest in this topic has been increasing over the past decade due to the trend towards higher accuracy, smaller-sized components. Linking material property acquisition and modelling in the nanometric scale with those on the micro-scale is a considerable challenge in material science in general and in micro-machining in particular. Due to computational limitations it is presently extremely difficult to inflate atomic level models and simulations to the micro-sized component dimensions. This detailed knowledge of material behaviour will provide the necessary insight to support process development, modelling and the optimization of critical ultra-precision machining processes. This paper presents a new methodology of providing a finite element model of the micro-cutting process with relevant material properties acquired from a newly developed molecular dynamics simulation model of a uniaxial tension test performed on silicon. Material properties such as yield stress, ultimate stress and modulus of elasticity are extracted from the stress–strain curve produced by the molecular dynamics model and automatically fed to the finite element model to evaluate the cutting forces required to machine a silicon wafer using different cutting parameters.