A Study on Ultrasonic Vibration Cutting of Difficult-to-cut Materials

Abstract

In this thesis, conventional ultrasonic vibration cutting (CUVC) and ultrasonic elliptical vibration cutting (UEVC) methods are studied and applied to two difficult-to-cut materials. Firstly, theoretical study reveals that the CUVC mechanism is influenced by: 1) tool vibration frequency, 2) vibration amplitude and 3) cutting speed. The increase in first two and the decrease in third parameters improve CUVC performance. The findings are substantiated by previous studies and experimental investigations in this study while cutting Inconel 718 using CBN tools. Secondly, the UEVC method is applied to WC using PCD tools to observe the effects of cutting parameters and tool geometry on UEVC performances and to characterize tool wear mechanisms. Lastly, study in the UEVC method demonstrates that the maximum thickness of cut (TOCm) of workpiece material has direct relationships with: 1) cutting speed, 2) tool vibration frequency, and 3) tangential and 4) thrust directional vibration amplitudes. The relationships are developed and substantiated by experimental investigations. Findings confirm that ductile cutting of brittle materials is possible applying the UEVC method.