Chatter Stability Model of Micro Milling With Process Damping

Abstract

This paper presents the prediction of cutting forces and chatter stability of micromilling operations from the material's constitutive flow stress and structural dynamics of the microend mill. The cutting force coefficients are identified either using previously presented slipline field or finite element methods by considering the effects of chip size, cutting edge radius, rake angle and cutting speed. The process damping caused by the plowing of round edge is modeled by finite element method. The frequency response function of the fragile micromill is measured through specially devised piezo actuator mechanism. Dynamic model of micromilling with the velocity dependent process damping mechanism is presented, and the chatter stability is predicted in frequency domain. The proposed models have been experimentally verified in micromilling of AISI 1045 steel.