Improvement of efficiency of stamp flushing method in ECM

Abstract In conventional ECM processes, electrolyte flow is used to flush out bubbles and sludge from the working gap. However, the electrolyte flow causes uneven distributions of bubbles and temperature, which result in deteriorated machining accuracy. Thus, ECM in a stationary electrolyte is ideal, while an efficient flushing motion of the tool electrode during a short interval between current pulses is needed to implement this. Hence, the authors developed the stamp flushing method. In this method, the gap width is shortened to extrude bubbles and sludge from the gap, while the conventional jump flushing method widens the gap width. Only a single pulse of which the duration is sufficiently short not to fill the gap with bubbles is supplied followed by the flushing motion. The authors have performed some machining experiments, which showed a higher efficiency with the stamp flushing method compared to the jump flushing method. Furthermore, the flushing mechanism in the stamp flushing method was elucidated. The flushing phenomena in the stamp flushing method were visualized and the effective flushing conditions were discussed.