Ball-end milling cutter design method towards the maximum material removal rate under surface roughness constraints

Abstract

Cutter design and selection, as one of the indispensable tasks in discrete parts' manufacturing process planning, has seldom been investigated in terms of high machining quality and machining efficiency. In order to fill this gap, this paper studies the influences of main geometric parameters of ball-end cutter (helix angle, flute number, cutter radius) on surface roughness and material removal rate (MRR). Firstly, it is revealed that the fundamental reason why the helix angle affects the cutting force coefficients is the oblique angle, not the axial height or axial position angle. And a novel method of cutting force coefficients prediction for newly designed cutter based on local helix angle is proposed. Then, the influences of cutter parameters on surface roughness and MRR are investigated by theoretical and experimental method. Based on this analysis, cutter evaluation models for machining quality and machining efficiency are established, respectively. Particle swarm optimization (PSO) is used as optimization method to search the optimal cutter. Finally, a novel cutter design method combined with cutter evaluation models is proposed to obtain better surface performance and machining efficiency. According to the experimental results, it can be proved that the cutter designed by this method can maximize MRR under the constraint of meeting the parts' surface roughness requirements. This is of great significance for improve parts' performance and reduce machining cost.