Use of wire bunch electrodes in electric discharge machining

Use of wire bunch electrodes in electric discharge machining
Kadir Dursun and Can Cogun
Department of Mechanical Engineering, Faculty of Engineering and Architecture, Gazi University, Ankara, Turkey
Abstract Purpose – In electrical discharge machining (EDM) process, the production of separate electrodes for rough, semi-rough and finish machining of dies and moulds having complex surfaces, results in high cost and long lead-time in manufacturing. The purpose of this paper is to describe the machining performance of electrodes formed by using copper wire bunches (WBs) positioned to conform the surface to be machined was experimentally and theoretically analyzed. In the study, the variations in the machining rate, electrode wear rate, relative wear and workpiece surface roughness were examined for various discharge current and pulse-time settings. Design/methodology/approach – Copper WBs positioned to conform the surface to be machined in electric discharge machining. The variations in the machining rate, electrode wear rate, relative wear and workpiece surface roughness were examined experimentally for various discharge current and pulse-time settings. The WB electrodes (WBEs) are proven to be satisfactory as electrodes for roughing operations in electric discharge machining. Findings – The increase in number of wires and pulse energy result in decrease of relative wear for each wire in the electrode. The increase in number of wires in electrodes causes increase in machining area and in machining time in WBE method. With the increase of discharge current and pulse time, the electrode wear rate and material removal values increase and machining time decreases. By using the mathematical models obtained from the result of the experiments, the electrode wear rate, material removal rate, relative wear and the set length of wires for the desired cavity profile can be calculated. The labor cost of electrode manufacturing in the WBE method is lower compared to conventional