Modeling and experimental analysis of cutting force in longitudinal–torsional ultrasonic-assisted milling of titanium

Abstract

This study proposed a novel milling technology assisted by longitudinal–torsional compound ultrasonic vibration to overcome the difficulties in the processing of Ti-alloy heterogeneous surfaces or molding surfaces. Using the ball-end milling cutter as the research object, the geometrical model of the milling cutter edge was established, in which an axial position angle was used as the main parameter. The instantaneous cutting thickness was derived based on the cutter path and the cutting force model of the ball-head milling cutter under the longitudinal–torsional compound vibration condition. Finally, using the longitudinal–torsional synchronous vibration cutter system with a resonant frequency of 35.476 kHz and a longitudinal-to-torsional vibration amplitude ratio of approximately 0.25, the milling characteristics of fixed-curvature Ti-alloy workpieces under the longitudinal–torsional compound ultrasonic vibration condition were examined. Results show that the application of the longitudinal–torsional compound ultrasonic vibration can remarkably reduce the radial force F x but impose almost no effects on the tangential force F y and the axial force F z .