Three degrees of freedom chatter stability prediction in the milling process

Abstract

Chatter in the cutting process has a great influence on workpiece surface quality, machining efficiency, and service life of the machine tool. This work presents three degrees of freedom (DOF) dynamic model applied to tool chatter for thin-walled structures in milling. Combined with dynamic cutting force modelling in the radial, axial and tangential directions, the stability chart was solved by adopting an improved semi-discretization method in time domain. And the stability prediction model considering regenerative effect was validated by cutting tests with specific axial depth of cut and spindle speed. The cutting experimental results performed at different axial depth of cuts were in accordance with predicted stability lobe diagram (SLD). Moreover, the effects of cutting contact angle and radial immersion ratio on SLD were also analyzed. The study results show that the dynamic model could make a good prediction of chatter stability, and the established approach is high efficient in predicting the chatter stability lobe considering the actual situation.