Electrical discharge machining is a tooling method that uses electrical energy to cut, drill, etch and machine metal parts and is one of the most accurate types of machining. Hard metals and other materials are difficult to machine cleanly with conventional mechanical-cutting methods and therefore EDM machining is used. The process erodes the material in the path of the EDM tool using electrical discharges, or sparks.
The “tool electrode” forms an arc to the “work piece electrode” as the two are brought closer together, creating the intense electric field which is responsible for removing material. Applications such as manufacturing molds and dies for die casting and forging, as well as parts and components for industries such as food and beverage, automobile, defense, electronics and medical are common uses of conventional EDM. Using a dielectric fluid bath to prevent unwanted sparks and to flush away machining debris, EDM cutting and drilling is able to produce parts with high tolerances and accuracy.
As there is no contact between the machine and the work piece, there is no potential for impact damage either, resulting in a high quality piece with minimal imperfections and wastage. EDM is typically used for electrically conductive materials and some which are commonly processed with CNC EDM include aluminum, copper, zinc, bronze, tin, silicon, titanium and stainless steel.
The actual electrical discharge machining is accomplished through carefully created sparks, which are electrical discharges that can generate heat anywhere from eight to twenty thousand degrees. A shaped tool, electrode or wire is used to generate the series of sparks, depending on the process. There is no actual physical cutting contact but rather a conductive path that is established between the electrode and the material which melts away the unwanted portions of the work piece.
Electrical discharge machining services are engineered towards specific applications. Different types of machining include sinker EDM which is used for more complex geometries and for holes and patterns or wire EDM which specifically cuts patterns and shapes through a selected part or assembly.
CNC machines are used to guide, monitor and control the electrical discharge machining process, as well as CAD and CAM software. Electrical discharge machining has advantages over other machining techniques due to its ability to create complex and intricate parts with a high degree of accuracy. Another advantage of electrical discharge machining is its ability to machine parts on an extremely small scale.