EDM Machining
EDM 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 for hard metals and other materials that are difficult to machine cleanly with conventional mechanical-cutting methods. EDM erodes the material in the path of the EDM tool using electrical discharges, or sparks. The "tool electrode" forms an arc to the "workpiece electrode" as the two are brought closer together, creating the intense electric field which is responsible for removing material. Wire EDM and sinker EDM are the two main types of EDM machining services. Some of the common applications for EDM machining include producing plastic molds, die casting dies from hardened steel and forging dies. Industries that benefit from the use of the EDM machining process include food and beverage, automobile, stamping, extruding, defense, electronics, aerospace and medical.
The actual EDM machining is accomplished through 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 contact between the electrode and the work piece, but rather a conductive path that is established between the electrode and the material. This process takes place in a bath of dielectric fluid, which prevents premature sparking and flushes away debris, conducts electricity between the electrode and the work piece and then flushes out the melted material. Sinker EDM is capable of boring holes into metal workpieces, creating holes, patterns and at times three dimensional objects, while wire EDM cuts patterns and shapes. Diverse materials that can be used in EDM machining include aluminum, copper, zinc, bronze, tin, silicon, titanium and stainless steel.
EDM machining services are engineered towards specific applications. Wire EDM is used for cutting shapes through a selected part or assembly. Sinker EDM is used for more complex geometries where machined graphite or copper electrodes are used to erode the desired shape into the part or assembly. CNC machines are used to guide, monitor and control the electrical discharge machining process, as well as CAD and CAM software. EDM 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 EDM machining is its ability to machine parts on an extremely small scale. While using this process, the work piece is not deformed from impact because there is no direct contact between the electrode and the material, and likewise the work piece is burr-free after completion and saved from heat damage because very little material-damaging heat is generated during the procedure.