Electro-discharge machining of mesoscopic parts with electroplated copper and hot-pressed silver tungsten electrodes

Abstract

Recent advances in the development of plasma etchers for silicon has brought machines to the market which are able to etch silicon with high etch rates (>5 µm min −1) at high anisotropy (taper of sidewalls <1.5 •). Micromachined silicon is therefore not only suitable for applications in micromechanics but it can also fill the gap which exists between conventional macromachining (milling, turning) with feature sizes usually >1 mm and microelectromechanical systems with feature sizes <100 µm. In this work micromachined silicon is used as a mold for electroplating copper and for hot-pressing silver tungsten. After removing the silicon, the copper or silver-tungsten is used as an electrode for electro-discharge machining. Using these process steps nearly any conductive material can be shaped, in particular magnetic materials like amorphous metal which are difficult or impossible to machine otherwise. The fabrication of the electrodes is described as well as the influence of the electrode material on the achieved quality of the final part.

Materials used for sinking EDM electrodes: a review

“…Electrical and thermal properties were excellent according to the authors, as was also the wear resistance of the electrodes. Stampfl et al [95] described a new method for producing copper-tungsten, where silicon is used as a mold for electroplating copper-tungsten. The authors reported that the electrodes made by this method are suitable to shape any kind of conductive material, especially amorphous metal, which are difficult to machine with conventional methods.…”

“…As described above, Stampfl et al [95] described a new method for producing silver-tungsten electrodes, where silicon is used as a mold for hot pressing silver-tungsten. Similar results as those with copper-tungsten electrodes were achieved.…”

Identification, Fuzzy Controller for Electrical Discharge Machine Servo System

“…The EDM process eradicates material through originating controlled sparks between an electrically conductive work piece and a shaped electrode. In the EDM process an electric spark is used to cut the workpiece, which takes the shape opposite to that of the cutting tool or electrode (Stampfl et al, 2000). Fig.…”

Applications of Microplasmas and Microreactor Technology

“…Wire electrodes as thin as 25 µm are used with advanced spark control limiting the 'overburn', the gap between tool electrode and work piece, to as little as 3 µm. The micro-EDM process has been used for fabrication of meso-scale parts of dimensions 10 µm to 100 µm from difficult-to-machine materials including hardened tool steel, titanium, tungsten, diamond, doped silicon, gallium arsenide and rare earth magnetic materials [3,4].…”