Development of an Economical System for Electrical Discharge Machining (EDM) in Water

Electrical discharge machining (EDM) is a non-traditional machining process which has been widely used to manufacture dies and molds in industries such as aerospace, automotive, and surgical. Since EDM does not make direct contact between the tool and the workpiece, mechanical stresses, chatter and vibration problems during machining are eliminated. Moreover, materials of any hardness can be machined as long as they can conduct electricity. However, the use of hydrocarbon oil (commonly used as dielectric in commercial EDM machines) liberates harmful vapours, which represents health and safe risk. Research in the last three decades has involved the use of water as dielectric and the advantages that this implies. Most of the equipment used to perform EDM in water is based on commercial EDM machines, originally designed for hydrocarbon oil as dielectric, and that have been modified to stand water. In this paper the development and design of an economical EDM machine to be used with water as dielectric is presented. The main objective was to design an economical, simple, and effective system with augmented capabilities to perform EDM in water. The EDM system has been developed and the design of the main components is described in this paper. Some experimental tests of EDM in water have been carried out and the results have proved the functionality of the system.