Development of a Damped Toolholder for Vibration-Assisted High-Precision Milling Using High Damping Metals

Ultrasonic vibration-assisted machining (UVAM) is one of the most promising innovations in high precision machining of advanced materials such as titanium alloys for aerospace applications or silicon carbide materials for the semiconductor industry. UVAM improves the process efficiency by increasing tool life through lower cutting forces and temperatures. However, in vibration-assisted milling applications, it is necessary to isolate the spindle system from the vibrations induced by the oscillation actor in order to maintain the long-term accuracy of the machine. This paper presents an innovative approach based on the integration of high damping materials into the toolholder to improve its damping capacity while maintaining the necessary stiffness. Therefore, the tool holder was developed with cylindrical damping inserts in a radial pattern with shrink fit connections. According to the results it was shown that the damping capability of a conventional toolholder can be improved without unacceptably reducing its radial stiffness compared to a standard toolholder geometry.