What is Electrical Discharge Machining (EDM)?

Makino CNC EDM Machine EDNC-43S for sale | price & specs | EquipMatching Ad  337909

Electrical discharge machining (EDM Machine) is a kind of machining operation used for shaping conductive workpieces into geometrically complex parts. Electrical discharge machines are particularly well suited for machining components which have complicated contours or subtle cavities that might be hard to produce along with other conventional machining equipment. The procedure involves supplying electricity to both the shaping tool as well as the workpiece after which bringing the tool into closeness with the workpiece, that is completely immersed inside a dielectric fluid bath. This proximity causes the electrical field intensity between the tool and workpiece to beat the strength of the dielectric fluid, and creates a number of electrical discharges together. These electrical discharges remove material in the workpiece, and the pattern or form of material removed relies upon the shape of the tooling electrode. After the machining operation, the dielectric fluid is replaced between the electrodes. Apart from acting as a dielectric backward and forward electrodes, the fluid also plays a key role in the machining process, as it is used to eliminate the removed material and cool the machined area. The character of the process is really that, while materials are being taken off the workpiece; the tooling electrode is also gradually eroded, making periodic replacement necessary.

The electrical discharge machining process is extremely precise and generally used in producing components that are typically complex and need extreme accuracy. Additionally, another area of application that EDMs perform above par is incorporated in the machining and shaping of hard or exotic materials for example titanium, Hastelloy, Kovar, Inconel, as well as hardened steel. However, the only caveat using the electrical discharge machining process is it can be only be used with conductive materials.

You will find essentially two types of electrical discharge machines, which differ in the type of tooling electrode that they are outfitted with. They’re sinker EDMs and wire EDMs. The sinker EDM, also known as a ram EDM uses a shaped tooling electrode to facilitate the machining process. This tooling electrode is created by conventional machining right into a shape that’s specific to the application it’s used for as well as an exact reverse from the contour around be machined into the workpiece. The tooling, typically machined from graphite, is used with an insulating fluid for example oil or any other dielectric fluids. This shaped tooling is connected to an energy supply and made to approach the workpiece electrode, creating electrical discharges between them, which cause erosion within the desired shape. This type of EDM is usually used for precise machining of complex 3D parts, for example injection molding, die tooling, along with other components that require exceptional accuracy.

The wire EDM, however, is definitely an electrical discharge machine that utilizes an excellent metallic wire, usually made from brass, which acts as a cutting electrode to accurately shape intricate, complex components from thick metal plates. The wire and workpiece are generally supplied with electricity and when the wire approaches the workpiece, electrical discharges occur between them. These discharges remove material in the workpiece in a shape that is similar to a cutting or slicing action. As the wire electrode is eroding along with the workpiece, it’s continuously fed in to the workpiece from a spool to make sure uninterrupted cutting operation. The wire is fed through two guides, typically made from diamonds, each placed above and underneath the workpiece electrode. These guides are movable on the 2-axis x-y plane and are CNC controlled for cutting. The cutting operation occurs on a workpiece that is completely immersed in a dielectric fluid bath, normally de-ionized water, which is used as a coolant and also to flush away the removed material. This machining process can be used to chop complex and complicated 2D shapes on thick metal parts, especially aspects of hard and exotic metals such as Inconel and titanium. Some components commonly machined using wire EDMs are stripper plates, custom gears, and other parts that should be intricately eliminate. However, the advent of upper guides and multi-axis freedom of movement within the newer wire EDMs, allows they to chop intricate tapers and transitional shapes too.

Related posts