EDM (electrical discharge machining) is a manufacturing process in which a desired shape is achieved by using electrical discharges (sparks). It can also be called spark eroding, burning, die sinking, wire burning or wire erosion. Through a series of electrical discharges between two electrodes separated by a dielectric liquid, material is rapidly removed from the workpiece. There are two electrodes, one called the tool electrode and one is called the workpiece electrode. The process works because neither electrode makes actual contact with the other.

Voltage increases between two electrodes, which causes the intensity of the electric field to exceed (at least in some places) the dielectric strength, allowing for current to flow across the electrodes. This is the same phenomenon as a capacitor (condenser) breaking down (also breakdown voltage). The electrodes lose material as a result. The liquid dielectric is usually conveyed into the inter-electrode volume once the current stops (or is stopped, depending on the generator type) to ensure that solid particles (debris) are removed and the insulating properties of the dielectric are restored. In this procedure, the liquid dielectric is added between the electrodes and this is called “flushing.” Also, after a current flow, the difference of potential between the electrodes is restored, so another liquid dielectric breakdown occurs.

There are several reasons to consider using wire erosion as a manufacturing process

The Effect of Wire Erosion on Internal Aperture Profiling & Machining

Manufacturers of high-tech components such as aerospace, oil & gas, satellite manufacture, formula 1 components, and other high-tech industries utilize wire erosion manufacturing to produce high-quality components.

With the requirement within these industries for sophisticated, precise machining of complex prismatic components with intricate internal detail, wire erosion machining is often the most appropriate machining process in these operations.

Hole, slot, slit, and gallery machining by wire erosion

Wire erosion manufacturing is an excellent choice for oil & gas industry components that require precision slotting, galleries, slits, and other intricate features. Electrical discharge machining can be combined with spark erosion manufacturing, or die sink manufacturing as it is also known, to produce a complete solution.

Using chemically treated materials for wire erosion machining

In order to avoid a compromise in component integrity caused by chemically treated materials, wire erosion and spark erosion have become the machining processes of choice for machining chemically treated materials that become surface brittle.

Machining of hardened materials using wire erosion

It can be difficult to machine materials that have been hardened, similar to chemical treatments. In order to address this issue, pre-hardening 5 axis machining, turning or milling operations are deployed to achieve component structure, and the post-hardened machining and finishing are performed using wire erosion manufacturing – before finishing and inspection.

Machines made with wire erosion for exotic, difficult-to-machine materials

The wire erosion manufacturing process can be used on exotic materials, such as titanium alloys, which are difficult to machine from the outset. In order to maintain the integrity of both material and components, the wire erosion manufacturing process is employed for delicate operations.