Analytical Modeling of Chip Geometry in High Speed Ball End Milling on Inclined Inconel 718 Workpieces

Abstract

Most often contoured surfaces inclined at several inclinations are generated using ballend milling of aerospace and automobile components. It is understood that the chip morphology and the corresponding cutting mechanisms change with a change in the toolworkpiece interactions on inclined surfaces. Analytical predictive models to accurately evaluate the undeformed and deformed geometries of chip in ballend milling are not available. Therefore, this work presents development of analytical models to predict the cutting toolworkpiece interaction as the workpiece inclination changes, in terms of undeformed and deformed chip cross sections. The models further evaluate instantaneous shear angle along any cross section of the toolwork interaction on a ballend cutter in a milling operation. The models illustrate evaluation of a chip segment and mechanism of its formation in ballend milling on an inclined work surface. It is observed that the chip dimensions, except deformed chip thickness, increase with an increase in the workpiece inclination angle. Also, a higher workpiece inclination results into an easy flow of the deformed chip over the cutting tool flank, which leads to a higher shear angle during the cut. The predictive chip geometry models corroborate 90% to the experimental results obtained at various workpiece inclinations.