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

Implementation of die-sinking EDM for precision machining of meso-micro-scale features with surface area smaller than 10 mm(2) down to 0.1 mm(2) is mainly restricted by electrode machining and electrode wear. In this work, micro-scale graphite electrodes with a projection area as small as 0.002 mm(2) and 1 mm 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. (C) 2015 Elsevier Inc. All rights reserved.