An Analytical Model for the Prediction of Chip Evacuation Force in Micro-Drilling

Chip evacuation is a critical aspect of the micro-drilling process, as the confined nature of the chips between the hole wall and flute can lead to clogging, increased thrust and torque, tool wear, and potential failure. This paper presents a physics-based analytical model for predicting chip evacuation force using principles of granular chip particle kinetics and energy transfer. The model incorporates material properties, tool geometry, and cutting conditions, while also accounting for the adhesion and drag effects due to scaling of drilling process geometry. Validation through micro-drilling experiments on hardened steel demonstrates strong agreement between predicted and measured chip evacuation forces. The model offers a generalized approach applicable to various work materials eliminating the need for costly calibration experiments.