Debris and bubble movements during electrical discharge machining

Debris accumulation in the discharge gap causes a poor machining stability and low production efficiency. Thus, an understanding on the mechanism of debris exclusion in electrical discharge machining is important. However, to date, this mechanism has not been fully understood because of the difficulty in observing debris movements in discharge gaps. The current study established a series of experimental devices using transparent materials to observe debris and bubble movements. Based on the observations, the mechanism of debris and bubble exclusion during consecutive pulse discharges is analyzed, and the effects of the electrode jump height and speed on the debris and bubble movements are investigated. In addition, the effectiveness of the debris and bubble movements on machining efficiency is discussed.

► Devices were established to observe debris and bubble movements in discharge gap.
► Mechanism of debris and bubble exclusion during EDM is investigated.
► Influence of debris and bubble movements on machine efficiency is discussed.