Download Electro Discharge Machining ppt. Check out and download the best Electro Discharge Machining ppt for you study. In Mechanical Engineering Electro Discharge Machining is one of the important Non conventional machining process also its one of the widely used process in production engineering.
EDM is a non-conventional machining technique uniquely used for cutting metals which are not possible to cut with traditional methods. EDM only works with materials which are electrically conductive. Delicate cavities and intricate contours which are difficult to produce with a grinder or other machines can be done with Electrical Discharge Machining or EDM. The cutting tool for EDM may be made of hardened too steel, titanium carbide or inconel or kovar.
Principles of EDM
Electrical Discharge Machining (EDM) is a controlled metal-removal process that is used to remove metal by means of electric spark erosion. In this process an electric spark is used as the cutting tool to cut (erode) the workpiece to produce the finished part to the desired shape. The metal-removal process is performed by applying a pulsating (ON/OFF) electrical charge of high-frequency current through the electrode to the workpiece. This removes (erodes) very tiny pieces of metal from the workpiece at a controlled rate.
EDM spark erosion is the same as having an electrical short that burns a small hole in a piece of metal it contacts. With the EDM process both the workpiece material and the electrode material must be conductors of electricity. The EDM process can be used in two different ways: 1. A preshaped or formed electrode (tool),usually made from graphite or copper, is shaped to the form of the cavity it is to reproduce. The formed electrode is fed vertically down and the reverse shape of the electrode is eroded (burned) into the solid workpiece. 2. A continuous-travelling vertical-wire electrode, the diameter of a small needle or less, is controlled by the computer to follow a programmed path to erode or cut a narrow slot through the workpiece to produce the required shape.