Theoretical and experimental investigations of ultrasonic vibration–assisted boring for titanium alloy

To effectively cope with the hard machinability challenges of hole caused by difficult-to-cut materials and high processing standards in aviation field, ultrasonic vibration–assisted boring (UB) methods with different modes are proposed. In this paper, the kinematics characteristics of UB were analyzed, the motion trajectory of tool was discussed. The comparison experiment of conventional boring and UB with longitudinal vibration and longitudinal-torsional vibration was performed to study the effect of ultrasonic field on the boring process, the influence of main parameters on boring force and surface roughness were investigated. The results show that UB can reduce boring force and surface roughness effectively, especially with the help of longitudinal-torsional vibration, compared with the conventional boring, the boring force could be reduced by 38.04–43.77%, and the surface roughness could be reduced by 25.48–41.47%. This study proves the feasibility of UB and provides theoretical and experimental reference for improving the surface quality of difficult-to-machine holes.