Parametric study on the tool inclination angle for side milling thin-walled workpiece edges based on finite element simulation

Abstract

Side milling thin-walled workpiece edges is an indispensible procedure in the continuous process chains for the high-efficiency machining of thin-walled functional parts, for example, the small- and medium-sized compressor blades. In these operation cases, the workpiece vibration is easy to occur due to the poor stiffness of the thin-walled structures, causing defects to the machined surface finish and even the dimensional accuracy of the thin-walled workpiece edges. To this problem, this study proposes the tool inclination method based on the adaption of the cutting force component in the lowest stiffness direction of the thin-walled workpiece, and it aims, first, to guarantee the machined surface finish which is mostly dominated by the workpiece vibrations mainly induced by the relatively high cutting forces and, second, to guarantee the high machining efficiency. The parametric study on the tool inclination angle for side milling the thin-walled workpiece edges was conducted by using the finite element simulations. First, the finite element models were elaborated and validated by the experimental results in terms of the cutting forces. Then, based on a series of finite element simulations, the effects of the tool inclination angle on the cutting forces adaption and its corresponding mechanism, that is, the chip formation variation, were investigated. Simulation results under the given conditions showed that the optimal tool inclination angle for the minimum absolute value of Fn was 26°. At last, the prediction feasibility for the best machined surface finish when side milling the low-stiffness thin-walled workpiece edges at the optimal tool inclination angle was well validated by the experimental results. The proposed tool inclination method with the solid end mill based on the finite element model to improve the machined surface finish is meaningful and feasible for the high-efficiency manufacturing processes of thin-walled workpieces.