Mirror Surface Finishing of Hardened Die Steel by High-power Ultrasonic Elliptical Vibration Cutting

Ultrasonic elliptical vibration cutting has recently been utilized in industry for finishing of various precision parts such as mirror surface finishing and precision micro machining of dies and molds. However, its application has been limited to high-cost ultra-precision machining, where depth of cut is typically in a range from a few micrometers to several tens of micrometers due to power limitation of the vibration device. To expand its application to low-cost mirror surface finishing with ordinary machining facilities, a high-power elliptical vibration device was developed in this research. The elliptical vibration cutting of hardened die steel was examined by applying the developed high-power elliptical vibration device with single crystalline diamond tools. Pick feed was kept to be 0.02 mm to obtain mirror quality surfaces, while depth of cut was increased up to 0.4 mm to verify performance of the high-power elliptical vibration cutting. By analyzing the experimental results, it was clarified that mirror surface finishing of the hardened die steel can be achieved at the large depth of cut with practically acceptable tool life.