TC4 titanium alloy has been widely used in aviation and aerospace industry because of its excellent comprehensive mechanical properties. However

the high plasticity and low thermal conductivity of TC4 lead to pronounced tool-chip adhesion

which is a key factor restricting the improvement of its milling performance. In this paper

a longitudinal-bending hybrid ultrasonic vibration assisted milling method is proposed to improve the milling performance of TC4

through the reduction of tool-chip adhesion accompanied by the controllable intermittent cutting realized by individually controlling the amplitude and phase of longitudinal and bending ultrasonic vibration of the cutting tool. Firstly

the kinematics principle of longitudinal-bending hybrid ultrasonic vibration assisted milling is analyzed theoretically. Based on this

the longitudinal-bending hybrid ultrasonic vibration tool is designed and manufactured. After assembly of the vibration tool with the high-speed spindle

the radial runout of the milling tool is less than 20μm. Then

a three-axis linkage equipment of longitudinal-bending hybrid ultrasonic vibration assisted milling is established

with which the vibration-assisted milling experiments of TC4 are carried out

and the experimental results are characterized and analyzed. The experimental results show that the applying of longitudinal-bending hybrid ultrasonic vibration to conventional milling effectively reduces the cutting force

the burr generation and the tool wear

while improving the surface machining quality

which demonstrate the feasibility of applying the longitudinal-bending hybrid ultrasonic vibration assisted milling in improving the milling performance of TC4 titanium alloy.