Study on Micro Reciprocated Wire-EDM for Complex Indexing Structure

Abstract In this paper, the machining method of complex indexing structure by micro reciprocated wire electrical discharge machining (micro reciprocated wire-EDM) is presented. A high-precise indexing mechanism is developed and clamped on the X/Y processing platform to enable the indexing rotation of cylindrical workpiece. To obtain good machining performance, the pre-experiments are performed to analyze the effects of open voltage, discharge capacitance, pulse duration and feed rate on material removal rate (MRR) and kerf width, and whilst the proper machining parameters are determined. Subsequently, the discharge gap under different workpiece thickness is studied because the workpiece thickness is varied when cutting indexing structure, which will result in different discharge gap. The obtained discharge gap is compensated in the tool path of a designed hexagonal microelectrode array with high aspect ratio. Lastly, the designed sample is successfully fabricated by the method. The result shows that the machining tolerance between -0.1 μm and +0.6 μm and aspect ratio with 17.5 are obtained.