About EDM Electrode Materials

EDM electrode materials and components consist of highly conductive and/or arc erosion-resistant materials such as graphite, copper or copper graphite. EDM is an acronym for electric discharge machining, a process that uses a controlled electrical spark to erode metal. EDM electrode materials include components made from brass, copper and copper alloys, graphite, molybdenum, silver, and silver tungsten. 

EDM electrodes are manufactured in variety of forms such as coated wire, tube shaped, or bar stock, depending on the EDM electrode materials used and the application. A brass electrode is easy to machine and can also be die cast or extruded for use in special applications. However, brass is not as wear-resistant as other EDM electrode materials, such as copper or tungsten, so it is typically used to make EDM wire. Copper is a common base material because it is highly conductive and strong. A copper tungsten electrode is used in resistance welding electrodes and in circuit breakers. A copper zirconium diboride electrode is similar to a copper tungsten electrode, but has much higher erosion resistance and is more expensive to produce. A tellurium copper electrode is easy to machine and is useful in applications that require an electrode with a fine finish. 

Other EDM electrode materials include graphite, silver, and molybdenum. A metal graphite electrode is the most common type of EDM electrode because it is easily machined, has high wear resistance and operating temperature capabilities, and is cost effective. A molybdenum electrode is typically used for special applications, such as small electrodes or EDM wire designed for high strength and arc erosion resistance. Silver is a highly conductive metal, and is used in conjunction with other EDM electrode materials such as erosion-resistant tungsten to make EDM electrodes for special applications. A silver tungsten electrode may be used in deep slot applications that function under poor flushing conditions. Tungsten has a high melting point, which makes it a useful EDM electrode material in combination with more conductive metals. A tungsten carbide electrode is a combination of tungsten and carbon bound together with a metal binder. Tungsten carbide and other metal carbides are used for EDM electrode materials because they have high hardness qualities and are wear-resistant.