Wire cutting machining (EDM) is a process of metal machining in which a tool discharges thousands of sparks to a metal workpiece. Instead of cutting the material, EDM melts or vaporizes it, leaving little debris and providing a very accurate line.
In tool and mould making, EDM is very popular due to its applicability especially for hard materials like titanium or for particularly complex shapes that are hard to achieve with milling.
Why Use EDM?
In practical terms, electrical discharge machining overcomes a major issue found in contact machining: hardness. In traditional processes, metal workpieces are made from special grades of hardenable tool steels machined in an anneal of soft state to facilitate cutting.
One the desired shape has been machined, the parts are then hardened by one or more heat treatments. This adds time, cost and can alter the finished parts’ dimensions, especially if the heat treatment process is not properly controlled. The advantage of EDM is that it can cut hardened materials and exotic alloys while also providing excellent surface finishes as a bonus. The result is often a reduced need for post-processing or surface treatment.