Electrical Discharge Machining (EDM), sometimes referred to as spark machining, spark eroding, burning, die sinking, or wire erosion, is a process of metal removal that defines a specific shape by actively melting away metal using a powerful electric spark. Electrical sparks cause material to be removed from a contoured shape from a tool or material and deposited in other places. EDM has evolved over the years from a relatively primitive technology with very few capabilities to one that covers a wide range of machining tasks.
The electrical discharge process begins with a machined die or tool made from a conductive material such as heat or electricity resistant metals or alloys. The tool is then connected to a power supply and submerged in a dielectric fluid such as oil or water. An electrical spark, usually from a spark gap, is then used to fracture the metal shape while it is still in the dielectric fluid, creating a spark stream and a tiny gas pocket at the interface. This process can be repeated many times allowing the material to be slowly cut away in a controlled manner.
One of the common EDM processes, known as wire erosion, is used for machining hard or delicate parts using thin metal wire as the cutting tool. This technology is especially suitable for cutting metals that would be too difficult to be processed using traditional machining techniques. With wire erosion, metal is cut by passing a thin wire made from a precious metal, such as tungsten or molybdenum, through the right coordinates in the metal shape. By passing a current through the wire, an electric spark is created which resembles a series of small blasts to sever small pieces of material. The action of this process is very fast and precise, with no heat generated and no burrs, so the final product has a smooth finish.
Wire erosion is a very efficient process, able to cut shapes as small as 0.002 inches in diameter with an accuracy of up to 0.0004 of an inch. It can also be used on a variety of materials, such as copper, iron, brass, aluminum, stainless steel, carbon steels, titanium and other alloys. The process is also ideal for producing complex shapes or intricate detail, or for machining intricate patterns including helical forms, tapers and stepped surfaces.
In conclusion, electrical discharge machining (EDM) is a cost effective and efficient way to produce intricate parts and shapes. Wire erosion, one of the common EDM processes, uses thin metal wire to cut precision shapes quickly and accurately. This method is suitable for materials such as copper, iron, brass, aluminum, stainless steel, carbon steels, titanium and other alloys. Additionally, the process is very precise and can produce shapes as small as 0.002 inches in diameter with an accuracy of up to 0.0004 of an inch. As such, it is an ideal choice for a wide range of machining tasks.
