Electrical Discharge Machining (EDM) is a precision machining process that uses electrical discharges, or sparks, to remove material from a workpiece. It is also known as spark erosion, spark machining, or wire EDM.
In EDM, a workpiece, typically made of conductive material such as metal, is submerged in a dielectric fluid (usually deionized water) and positioned close to an electrode, known as the tool or the electrode tool. The tool is made of a conductive material and is controlled by a computer numerical control (CNC) system.
When the EDM process begins, a high-frequency electrical voltage is applied between the tool and the workpiece. This voltage creates a spark discharge or a series of sparks between the two, resulting in the localized melting and vaporization of the workpiece material. The dielectric fluid helps to flush away the eroded material and cools down the workpiece and the tool.
As the sparks occur, very small craters are formed on the workpiece surface, and the process continues to erode the material until the desired shape or feature is achieved. The EDM process is highly controlled, and the sparks can be precisely controlled to remove material with high accuracy and repeatability.
EDM is particularly useful for machining complex shapes, hardened materials, or materials that are difficult to machine using conventional cutting tools. It is commonly used in industries such as aerospace, automotive, mold and die manufacturing, and electronics, where high precision and intricate details are required.
There are different variations of EDM, including wire EDM, where a thin, electrically charged wire is used as the electrode tool, and sinker EDM (also called plunge EDM), where the tool is shaped to match the desired shape and directly contacts the workpiece. Each variation has its own advantages and applications.
EDM is a versatile and precise machining technique that allows for the production of intricate and complex parts with high accuracy, even in challenging materials.
