A novel approach to efficiency determination in micro electro discharge machining

The need for high-aspect ratio micro structures in hard to machine materials is constantly growing. Electro-Physical machining processes such as EDM offer distinct advantages to conventional machining technologies such as independence of material hardness, but are difficult to control for high-precision and micro applications. It is therefore of great importance to provide means of fast and stable machining in Micro-EDM, e.g. optimize process and discharge efficiency. In this study, a novel approach to characterize erosion efficiency in Micro-EDM is made by recording erosion current and voltage with high resolution and long recording time. The paper presents the objectives of pulse shape classification for micro-EDM and lines out how a rating of erosion efficiency can be realized by studying the number and sequence of current and voltage of the erosion pulses. Thus, process analysis can be improved and optimized parameters can be adopted to the process state, eventually leading to an on-line process control.