Overhang length effect during micro-milling of Inconel 718 superalloy

Abstract

The accuracy of machining force relies on the accuracy of the cutting force coefficients which are determined by calibration experiments and are related to cutting tool-workpiece material couple. To this end, a mechanistic model was established to anticipate machining forces that occurred during micro-milling under different tool overhang lengths. This study assumed that the cutting force coefficients varied with the tool overhang length, and this assumption was proved by some micro-milling experiments. Force coefficients were computed by linearly fitting the experimental force data. In the current work, also wear on tool and burr formation were observed as functions of feed per tooth and overhang length. The overhang length of 15 and 20mm significantly reduced the diameter of the micro-tool as compared to the overhang length of 10mm. The obtained results showed that cutting forces and top burr width increased with the increasing overhang length. It was also found that the values of cutting and edge coefficients differed with the overhang length.