Investigating Adhesion Phenomenon of Debris during Micro Hole Drilling with EDM

Abstract

The debris and bubbles accumulation cause the abnormal discharge increase, which limited the feed depth during drilling the micro hole with EDM. It was confirmed that most of the debris adhere to the negative polarity from the direct observation. However, apart from the phenomenon of adhesion to the negative electrode, the other characteristics of the debris are little known. In this paper, the characteristics of the adhesion are investigated by switching the tool polarity, which is helpful to better study and analyze the reasons why the debris are difficult to exhaust from inter-electrode area during drilling deep micro-hole by EDM.