Micro-EDM-milling Development of New Machining Technology for Micro-machining

This paper investigates the physical basis and the industrial feasibility of micro-EDM-milling; the characteristics of this innovative technology are the following: (i) electrodes are of standard size — it is no more necessary to prepare electrode as in die sinking, (ii) electrodes are of small diameter (<0.8 mm) and long (∼40 mm) - this make them flexible, (iii) electrodes are straitened by a dynamic self-centering effect when rotating at high speed, (iv) work piece material is removed by the sparking only at the tip of the electrode and (v) electrode wear is compensated by programmed declining trajectory.All this makes Micro-EDM-milling a quite unconventional and original technology. The most innovative point is the use of long, thin and low cost electrodes. Its interest is due to the absence of cutting forces, this technology allows machining deep cavities of high precision without any risk of tool break.Micro-EDM-milling has a strong innovative potential: today there is no machining technology that is able to perform so accurate, fine detailed cavities with such high aspect ratio (h/l > 30). This new technology could be placed as an independent machining technology, but also as a complement to die-EDM-sinking as well as to high speed milling.