what is wire EDM used for,process and accurate

What is Wire Electrical Discharge Machining?

Wire electrical discharge machining (WEDM) uses a metallic wire to cut or shape a workpiece, often a conductive material, with a thin electrode wire that follows a precisely programmed path. Typically the electrode diameters range from .004″ – .012″ (.10mm – .30mm), although smaller and larger diameters are available.

During the wire cutting process there is no direct contact between the wire and the workpiece which allows for machining without causing any distortion in the path of the wire, or the shape of the material. To accomplish this, the wire is very rapidly charged to a desired voltage. The wire is also surrounded by deionized water. When the voltage reaches the correct level, a spark jumps the gap and melts a small portion of the work piece. The deionized water cools and flushes away the small particles from the gap.

How Wire-Cut EDM Works

EDM cutting is always through the entire workpiece. To start wire machining it is first necessary to drill a hole in the workpiece or start from the edge. On the machining area, each discharge creates a crater in the workpiece and an impact on the tool. The wire can be inclined, thus making it possible to make parts with taper or with different profiles at the top and bottom. There is never any mechanical contact between the electrode and workpiece (see above). The wire is usually made of brass or stratified copper, and is between 0.1 and 0.3 mm diameter.

Depending on the accuracy and surface finish needed, a part will either be one cut or it will be roughed and skimmed. On a one cut the wire ideally passes through a solid part and drops a slug or scrap piece when it is done. This will give adequate accuracy for some jobs, but most of the time, skimming is necessary.

What types of shapes can a wire EDM machine produce

A wire EDM machine is a type of CNC machine that can move along four independent axes to generate taper cuts. For example, a stamping die can be machined with 1/4 degree taper or a mold with one degree taper in some areas and two degrees in another with precision. Extrusion dies or nozzles and horns can be cut with constantly changing tapers. For example, a detailed shape on the top of the work piece can transition to a simple circle on the bottom.

Uses for Wire Electrical Discharge Machining

Our wire cut EDM services are ideal for delicate or small work pieces that may be damaged during conventional machining or other traditional techniques:
Thick parts requiring good finishes and/or accuracies.
Complex shapes or narrow slots
Larger parts that need to hold accurate tolerances
Delicate, hard, exotic/expensive or weak materials

advantages of Wire Electrical Discharge Machining

Wire EDM offers many unique advantages, making it the go-to machining process for producing a variety of different parts and components. First off, Wire EDM’s high precision allows it to create very complex shapes. And its ability to work with hard materials means that it can bring those materials to close tolerances as needed.

Since Wire EDM can handle a high level of complexity, the process can be used to create very small, intricate pieces. And with no direct contact occurring between the tool and the actual part being shaped, it’s easier to achieve a smooth surface finish that is accurate and burr-free.

And, perhaps most importantly in some instances, parts manufactured through EDM are ready for use immediately upon completion of the Wire EDM process.

So, why use Wire EDM?

Wire EDM can work hard materials and alloys of increasing thickness without compromising the surface finish of the resulting product.

As a noncontact machining process, Wire EDM can achieve high-quality finishes, thereby reducing the need for post-processing procedures and surface treatments, which are often necessary with other manufacturing processes.

Because Wire EDM is a computer numerical controlled (CNC) machining process and uses automated software to program functions, the process produces accurate, predictable, and repeatable results during every production run.

Wire EDM can also accommodate small production runs requiring tight tolerances, as is often the case in the aerospace and medical equipment industries.

Wire EDM is more cost-effective and time-efficient than other processes available.