Choosing EDM Electrode Material
Electrical Discharge Machining (EDM) is a process that produces desired shapes from metal that can't be machined using traditional techniques. EDM machines use a series of rapidly recurring current discharges between electrodes and workpieces to create tiny plasmas zones that melt and remove material.
There are many electrode materials available for EDM applications. Some of the most popular are graphite, copper, titanium, brass, silver, and tungsten carbide.
Choosing the best electrode for your EDM application is an important decision that requires careful consideration. There are several factors that influence this choice including conductivity, corrosion resistance, hardness, form, and size.
Some of the common types of electrodes include single hole, two and three channel, wire insert, Y-type, and web type. Each of these different types has its own purposes and design.
Single Hole Electrodes are used primarily for hole burning applications. Because they don't have any internal walls, they burn away more material than multi-channel electrodes.
Two and Three Channel Electrodes are designed to be similar to single hole electrodes in their function and design, but with a wider external diameter. They typically burn away less material than a single hole electrode, but have more flushing capabilities.
Wire Insert Electrodes are inserted into single hole electrodes to make them function more like a two or three channel electrode. They require a greater amount of material to produce, but they have more flushing characteristics and can be made more easily.