Investigation on tooling geometrical effects of micro tools and the associated micro milling performance

Abstract

In micro scale cutting, tooling geometry plays a significant role in determining machining quality and tool life, and the knowledge of tooling geometrical effects on process performance potentially benefits engineers on improving tool designs and selecting optimum cutting conditions. This research aims to comprehensively investigate tooling geometrical effects on the process performance in micro milling using a finite element method supported with well-designed cutting trials. In the study, a benchmark three-dimensional tooling model, incorporating rake angle, relief angle, helix angle, diameter and cutting edge radius is initially developed for simulating the micro milling process under large deformations. The simulation is then experimentally validated and the predicted micro chip formation and cutting forces are in reasonable agreement with measured results in cutting trials. Furthermore, finite element-based simulations are performed under different helix angles, rake angles and cutting edge radius, and comparisons of cutting forces, tool stresses, tool temperatures, chip formation and temperatures are presented and discussed. It is found that the cutting edge radius is the most influential factor on the tool’s process performance, followed by helix angle, and rake angle has less effect.