What is Wire EDM?

Wire EDM(Electric Discharge Machining) is a thermal machining process that uses an electrically charged thin brass wire as an electrode to cut any material that will conduct electricity. Because there is no mechanical force used to remove material, EDM is considered to be a non-conventional machining process. The wire never actually touches the material being cut. Instead, the current between the wire and the material creates a plasma that vaporizes the material being cut. During the process, the wire is also eroded, so new wire is constantly run past the part, and can not be re-used. The process uses a dielectric fluid, usually deionized water, to flush away the small particles removed from the part and the wire, as well as for cooling.

Wire EDM is a relatively slow process, but it has unique advantages over other processes. One advantage is that it can cut hard materials, like hardened tool steel, or carbide. Another advantage is that it can cut complex profiles with small details through thick material that would be difficult or impossible by any other method. Typical wire diameters range from .006-.012 (.152mm-.305mm). It is also extremely accurate. Tolerances of +/-.0005 (.013mm) can be held with a rough cut alone, and with skim cuts, it is possible to hold tolerances of +/-.0001 (.0025mm). Because there is no mechanical force being applied to the parts, it is also possible to cut extremely small and delicate parts. Although it is technically a thermal process, it is precisely controlled and focused, which allows it to cause almost no heat affected zone.

Many older machines are simply 2 axis machines, with an upper and lower wire guide holding the wire vertically. Most newer machines, however, are capable of moving the upper and lower guides independently. This allows the machine to tilt the wire. This is often used to cut tapered relief at a specified angle for die blocks, and is considered 2-1/2 axis. Some machines can also move the top and bottom in completely different shapes, for example, cutting a circle on the top of the part, and a square on the bottom. This is considered to be 4 axis, and is capable of cutting even more complex parts.



2017 All rights reserved.     Chicago Web Design