Chatter Stability Improvement in Micro Milling with Axial Vibrations

Productivity in machining operations is limited by chatter, which is caused by interactions between the tool and the workpiece. In order to suppress chatter, increased dynamic stiffness and reduced forces are vital. In this study, we employed the vibration assisted machining technique with axial vibrations to improve the dynamic stiffness of the micro end mills. Experimental modal analysis was performed on the tool, with and without the vibrations. It was found that vibration applied in the axial direction caused changes in dynamic properties. Micro milling chatter stability was predicted by measuring FRFs of the tool while external vibrations were applied. Experiments were performed to verify the prediction, and the results showed that the vibration assisted milling can increase chatter stability.