Mechanistic modeling of micro-drilling cutting forces

This paper presents a mechanistic model for micro-drilling cutting forces that includes the cutting edge radius and the minimum chip thickness size effects. The proposed model considers three different cutting regions, i.e., ploughing-dominant, transition, and shearing-dominant, based on these size effects. Specific normal force and specific friction force coefficients have been determined through model calibration using micro-drilling experimental results. Model is validated with micro-drilling experimental results of different cutting conditions and of different machining environments. Comparisons of model simulated and experimental results show that ploughing force contributions are significant, especially at low feed rates. The proposed model has also been applied to characterize size effects in micro-drilling.