Three-Dimensional Micro Machining by ECM.

Abstract

Electrochemical machining (ECM) has an advantage of no tool wear. On the other side, it is difficult to carry out micro machining in ECM, because the electrode gap in ECM is large. In this paper, electrochemical micro machining with the developed electrode gap control system is demonstrated. The narrow gaps make the control of the process much more complex than normal ECM. Preliminary ECM experiments are carried out in order to investigate a proper condition of machining process. Small hole is machined by using a 0.2mm Ni rod. Drilling time and electrode gap is measured. An optimum machining condition of ECM is determined in terms of machining voltage, machining pulse length, amplitude of electrode for flushing out a contamination, and electrolyte concentration. After preliminary ECM experiments, three-dimensional micro machining is carried out under the optimum condition. First, prismatic electrode whose base is 200μm square is machined by ECM. Next, three-dimensional micro machining is carried out by scanning the prismatic electrode. Three-dimensional shape that is sub-millimeter order is successfully machined.