For several decades now, electrical discharge machining (EDM) has been the solution for machining intricate parts and materials resistant to traditional machining methods or by necessity of design. This non-conventional process is one of the most efficient and cost-effective manufacturing methods since it delivers an extraordinary level of accuracy and unmatched precision. It works on parts that are electrically conductive, regardless of their hardness. EDM allows manufacturers to create complex shapes from hard materials such as titanium, stainless, steels, tool steel and other hardened alloys. There are three types of EDMs: Fast hole drilling EDM (Hole Poppers), Sinker EDM (Sinkers), and Wire EDM (Wires). However, for this article, we'll be looking in depth at Wire EDM.
Also known as spark eroding or spark machining, Wire EDM is a machining process where an electrically charged single strand wire is constantly fed within a dielectric fluid (usually deionized water) the resulting discharge when presented by the CNC in close proximity to the grounded workpiece is used to cut a conductive material. The wire is moved closer to the part being worked on to produce electric sparks that cut, or rather erode, through the metal. They are flushed and usually immersed in deionized water to get rid of the particles, cool the wire from breakage and control the sparks.
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When the wire is brought closer to the conductive metal rapid electrical discharges are produced. The discharges erode the metal on the focused areas, leaving no blemishes or deformations. The CNC controls the path the wire follows producing a contoured path bound only by the size of the wire itself (usually 0.,010” in diameter).
The use of precisely focused electrical discharges makes it possible to make complex or intricate shapes and patterns. Wire EDM machines can make different shapes, such as contours and holes, even on the hardest and the most fragile materials.
Unlike a vast array of fabrication processes that use impact to cut through materials, Wire EDM leverages thermal discharges to cut through parts. This means that the end product will not be deformed, distorted, or have any side effects of deformation caused by brute force in material removal.
When you use Wire EDM, you'll not have to use a lot of energy to cut even the most rigid materials. Additionally, you'll reduce material wastage since the process only removes the targeted particles only. Your cutting kerf (cut width) is usually less then 0.015”. Also, you don't need other machines for post-processing since the method delivers precise and accurate cuts.
The best part about Wire EDM is that your final product will not need to be passed through other processes for them to be complete such as grinding, honing etc. The method delivers high levels of accuracy and precision, especially on the smallest pieces.
The other benefit of Wire EDM is the fact that you can achieve high tolerance regardless of the material you’re working on. You can easily achieve tolerance of +/- 0.0005” with some machines that offer tolerances down to a few microns.
Pros and Cons of Wire EDMs
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Common Application of Wire EDMs
Since Wire EDM is ideal for creating small delicate items, its application is widely spread. However, it is mostly used in:
At Southern Fabricating Machinery Sales we are experts in EDM with several Toolmakers and Application Engineers on staff to assist in your Wire EDM decisions. Click below or call us today for more information on how to add the capability of Wire EDM in your shop.