Planarization of a Layer Made by Using Electrical Discharge Machining

This paper describes a new method of surface modification by EDM to create a hard surface on a workpiece and planarization of a layer. When a metallic material that makes hard carbide is used as an electrode in EDM, a hard layer can be made under certain condition. The process begins with the electrode wear by heat of the electrical discharge. Then the worn electrode material becomes hard carbide. The carbide piles up on the workpiece and becomes a layer. The layer formed by two or more electrical discharges has a problem that performance of the layer, its roughness and hardness, is not enough. Then, in order to improve the layer performance, the influence that a gap width exerts on the layer performance was studied. The increase in the gap width resulted in improving the layer performance.