Topography prediction of resilient parts after flank milling with chamfered tools

Chamfered milling tools are commonly used in industrial machining. They stand out due to a considerable gain of process stability, which results in a higher material removal rate compared to non-chamfered tools and therefore in a higher process productivity. Especially the aerospace industry with high material removal rates benefits of an increased productivity by the introduction of chamfered cutting edges. The wide use of chamfered tools and the high quality requirements in the aerospace industry require a model able to predict the surface topography of machined parts with respect to a chamfered cutting edge. To determine the deflection of resilient parts, the effect of the chamfer on the process forces has to be taken into account. This paper presents an analytical model to predict the surface topography of thin-walled, resilient parts after flank milling. Based on mathematical descriptions of the tool kinematics the trajectories of the cutting and the chamfer edge are described. They are used to determine the theoretical engagement conditions and to describe the undeformed chip geometry. Furthermore, the influence of a runout of the tools is considered. The undeformed chip thickness is used to calculate the milling forces along the cutting edge and to predict the resulting deflection of the workpiece. The model presented determines the 3-dimensional topography of the surface by merging the surface profile in feed and the deflection of the workpiece in feed normal direction. The model offers a fast approach for the determination of the influence of the chamfer on the surface topography and a change of the process forces.