Compared to ultrasonic vibration, low-frequency vibration can be easily realised, since there is no need for resonant systems.
Tests were conducted to characterise the effect of a LF-vibration on the machining of bore holes.
While the acceleration of process speed is in the region of 10% compared to conventional machining, a larger contribution can be seen in stabilising difficult geometries and reducing geometrical errors and process instabilities, which can be observed by a reduction of the machining time variation on the order of >50% (Fig. 5, Section (2)).
However, the specific machine tool setup has to be taken into consideration when choosing the vibration frequency in order to avoid a negative interaction with the gap width regulation. Section (1) in Fig. 5 shows this phenomenon.
Fig. 5. Low-frequency vibration aided ตEDM; effects on machining time t and its deviation