Die-Sinking Electrical Discharge machining as Final year Project

日期 : Jan 2017 - May 2017

Electrical discharge machining (EDM), also known as die sinking is a manufacturing process whereby a desired shape is obtained by using electrical discharges (sparks).Material is removed from the workpiece by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric liquid and subject to an electric voltage. For a long time ED machining was the only possible method for hardened steels. High speed technologies have improved the potentials of a milling method, but the shape depth still sets certain limits.Die-sink ED machining technology does not set this kind of limit, because there are no notable mechanical stresses on the cutting tool. The main attraction of EDM over traditional machining processes such as metal cutting using different tools and grinding is that this technique utilizes thermoelectric process to erode undesired materials from the workpiece by a series of discrete electrical sparks between the workpiece and the electrode. The sinker EDM machining (Electrical Discharge Machining) process uses an electrically charged electrode that is configured to a specific geometry to burn the geometry of the electrode into a metal component.Generally the work-piece is made positive and the tool negative.Hence, the electrons strike the job leading to crater formation due to high temperature and melting and material removal.Similarly, the positive ions impinge on the tool leading to tool wear.In EDM, the generator is used to apply voltage pulses between the tool and job.A constant voltage is not applied. Only sparking is desired rather than arcing.Arcing leads to localized material removal at a particular point whereas sparks get distributed all over the tool surface leading to uniform material removal.