Sinker EDM Machining Process
The sinker EDM machining (Electrical Discharge Machining) process uses an electrically charged electrode that is configured to a specific geometry to burn the geometry of the electrode into a metal component. The sinker EDM process is commonly used in the production of dies and molds.
How Sinker EDM works
Two metal parts submerged in an insulating liquid are connected to a source of current which is switched on and off automatically depending on the parameters set on the controller. When the current is switched on, an electric tension is created between the two metal parts.
If the two parts are brought together to within a fraction of an inch, the electrical tension is discharged and a spark jumps across. Where it strikes, the metal is heated up so much that it melts.
Innumerable such sparks spray, one after the other (never simultaneously) and gradually shape the desired form in the piece of metal, according to the shape of the electrode. Several hundred thousand sparks must fly per second before erosion takes place.
Die-sinking EDM Machining
In the case of die-sinking EDM, the required shape is formed negatively in the metal with a three-dimensional electrode. By superimposed movements in the main axes x, y, c, z, the most varied shapes, indentations and cavities are created, such as cannot in part be achieved by any other machining system.
For example, a helicoid cavity or a rectangular hole in one single steel block or the machining of an extremely thin, hardened steel sheet that may not be subjected to any mechanical pressure.