A strategy for low electrode wear in meso–micro-EDM

Abstract

Implementation of die-sinking EDM for precision machining of meso–micro-scale features with surface area smaller than 10mm2 down to 0.1mm2 is mainly restricted by electrode machining and electrode wear. In this work, micro-scale graphite electrodes with a projection area as small as 0.002mm2 and 1mm length have been machined. Process parameter analysis is carried out to analyse the wear behaviour of micro-scale graphite electrodes during erosion. Pulse duration, pause duration and rising current slopes have been found to be the primary parameters affecting the electrode wear. A low electrode wear strategy consisting of the wear neutral pulse packets is developed for erosion of micro-scale cavities and slots using graphite electrodes. Resource efficiency achieved through low electrode wear during roughing enables die-sinking EDM as a potential economic and energy efficient micromachining process.