Influence of vibration conditions on tool life in low-frequency vibration cutting of difficult-to-cut materials

抄録

Low-frequency vibration cutting technology can actively generate an intermittent cutting process in which chips are broken up by vibrating the tool in the feed direction synchronized with the spindle rotation. The sinusoidal oscillation superimposed to feed drive motion triggers cutting thickness fluctuations so that air cutting occurs. To attain efficient and practical machining, selection of appropriate conditions for low-frequency vibration cutting is important. From a practical point of view, it is necessary to analyze the cutting process for its effects on tool wear as well as chip breakup. Low-frequency vibration cutting has been reported to reduce average cutting force and average cutting temperature. On the other hand, few studies have analyzed the effect of tool trajectory on the tool life, and thus the mechanism has not been fully clarified. In this study, the effects of low-frequency vibration on the tool life in turning operations were experimentally investigated for carbon steel, stainless steel, and titanium alloys. In low-frequency vibration cutting of ductile materials such as carbon steel and stainless steel, tool damage was significantly improved by designing an intermittent cutting process with large amplitude. On the other hand, the tool life for titanium alloys was deteriorated in low-frequency-vibration cutting. The experimental results indicated that the higher the vibration speed, the faster the tool wear progression in titanium alloy machining. Model-based analysis of the cutting force revealed a characteristic mechanism of the flank wear development that depends on the tool trajectory with low frequency vibration.