How Does Electrical Discharge Machining (EDM) Work and Its Advantages
What is EDM?
You may have come across terms such as spark machining, die sinking, wire erosion, or spark eroding. Some engineers and manufacturers use these terms to refer to electrical discharge machining (EDM). But what is EDM? To simply put, EDM involves removing excess material from a workpiece with the use of thermal energy.
How Does Electrical Discharge Machining Work?
While the definition may seem simplistic, the physical process is a little bit more complex. The removal of material from a workpiece using EDM occurs through a series of recurring rapid current discharges between electrodes. These electrodes are separated using a dielectric fluid. Then, a voltage is sent through the dielectric fluid. It is important to note that EDM manufacturing only works for electrically conductive materials.
One of those electrodes serves to change shape to fit the exact purpose. This electrode is the workpiece electrode or the “anode.” The other electrode is the tool-electrode or the “cathode.” The basic principle behind this process is the erosion of the material with a controlled electric spark. For this to occur, the two electrodes must not come in contact.
There is the application of potential difference across the workpiece and the electrode in pulse form. As the electrode moves closer to the workpiece, the electric field present in the small gap between them increases. This continues until it reaches breakdown volume.
The electrical discharge causes extreme heating of the material. The heating leads to the melting away of some parts of the material. A steady flow of the dielectric fluid helps to remove the excess material. The liquid also assists in cooling during the machining process.
Advantages of Electrical Discharge Machining
1. Work on Any Type of Electrically Conductive Material
When you think of EDM manufacturing, the first thing that will come to your mind is its ability to work on a wide range of materials. As long as your material is electrically conductive, EDM is always the right process. This makes it possible to machine parts that are difficult for traditional machining methods. These include parts made from titanium and tungsten carbide.
2. No Mechanical Force is Involved
Another crucial benefit is that no mechanical force is put into the workpiece. Therefore, you don’t have to worry about producing fragile outlines. This becomes easy because there is no need for high cutting force before removing the material. Since no contact occurs between the tool and the workpiece, there is no issue of mechanical stress.
3. Enables Various Shapes and Depths
With EDM, reaching shapes and depths seems impossible with a cutting tool. It is an effective method for deep processing with very high tool lengths and diameter ratios. You can easily cut sharp internal corners, narrow slots, and deep ribs with the EDM process.
4. Encourages Better Surface Finish
Manufacturers also argue that injection molding surface finish is often better with EDM than traditional methods. This may be true because the EDM process gives surfaces high precision and fine finishes.
5. Work on Hardened Material
Other conventional machining processes need to be done before hardening the workpiece. On the other hand, EDM works perfectly on hardened material. Therefore, it is easy to avoid any potential deformation from heat treatment.
EDM manufacturing, being a great part-production option, definitely has lots of advantages in creating high-precision parts with desired shapes. If you have complex parts to produce, consider EDM process or pick SmarterFab focuses on high precision rapid prototyping service.