EDM is a cutting technology that uses the effects of erosive electrical discharges. This process only be used on good conductors, mainly metals. Machines designed to perform this type of processing are called EDM machines.
(def. EDM from wikipedia)
Electrical discharge machining (EDM)
EDM is a cutting technology that uses the effects of erosive electrical discharges. This process only be used on good conductors, mainly metals.The EDM process, is quite a common mechanical process as it allows the machining of very hard metals (particular steels) or metals with surface treatments to increase the hardness. It is possible to work very hard metals and create very specific profiles, as the tool that creates the cut in the material is an alloy wire of ø = 0.025 mm. This cutting process allows the creation of profiles otherwise impossible with normal machining by swarf removal.
The process is a very simple principle and consists of moving the tool through the piece being cut (wire in the case of wire EDM and the machine head in the case of die-sinking EDM), all immersed in a dielectric liquid.
The electrode can therefore be of two types, a simple wire or an electrode of a form defined by the user; the latter allows the creation of details complementary to the matrix itself. AR COSTRUZIONI MECCANICHE has a number of machines for wire EDM, one of which with the capability of inclined cutting, for a series of even more complex profiles. In this type of machining, the wire, which acts as a tool, is loaded onto the machine as a wrapped coil and is changed continuously.
This wire is in fact subject to wear caused by the passage of the electric current, in particular the stress caused by expansion. Should the cutting piece of wire not be continuously replaced it would frequently break.