FEM analysis of ultrasonic-vibration-assisted turning and the vibratory tool

Ultrasonic assisted turning (UAT) is an advanced method developed for machining tough and brittle materials such as supper-alloys, ceramics and glass. Using MSC-Marc and Ansys, the authors studied machining of IN738 with a tool vibrating at ultrasonic frequency. The machining forces and stresses acting on the workpiece during the process, and the effect of process parameters such as cutting speed, tool geometry and vibration amplitude were investigated. The authors also worked out the material and the optimum configuration of the vibratory tool being able to operate at an ultrasonic frequency within acceptable range. The results indicate that the forces and the stresses acting on the workpiece follow periodic changes during UAT and are augmented with an increase in the ultrasonic vibration amplitude or the cutting speed. The clearance angle has no significant effect on the magnitude of the machining force, but higher forces are produced with smaller tool rake angles. Conical-cylindrical aluminum horns with concentrically attached tool insert deliver more satisfactory performance. (C) 2007 Elsevier B.V. All rights reserved.