EDM Process
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.
Conventional EDM
In the EDM process an electric spark is used to cut the workpiece, which takes the shape
opposite to that of the cutting tool or electrode. The electrode and the workpiece are both