Electric discharge machining (EDM) is a special processing method that uses the electric erosion effect generated by the pulse discharge between the two electrodes immersed in the working fluid to erode conductive materials. Tool electrodes are usually made of electro-corrosion-resistant materials with good conductivity, high melting points, and easy processing, such as copper, graphite, copper-tungsten alloy, and molybdenum. During the machining process, the tool electrode also has a loss, but it is less than the erosion amount of the workpiece metal and even close to no loss.
