EDM is a non-standard and exceptionally precise process of electrical discharge machining, in which the object being machined from a typically conductive material has characteristics resulting from the controlled erosion of the material by electrical discharges (sparks). The basic assumption of electrical discharge machining involves two electrodes (the main electrode and the working electrode). When the intensity of the field between the two electrodes is high enough, the dielectric breaks down, current flows and material is removed from both electrodes. It should be emphasized that the current flow between the electrodes is not constant. Electrical discharge machining is exceptionally accurate for the object being machined. Why is it worth using electrical discharge machining? What are its advantages and what should you pay attention to? We write about this below!
Electroerosion processing is a great method
An increasing number of entities are using the EDM (Electrical Discharge Machining) method for plastics. It is mainly used in industries that require the creation of precise parts. This solution has proven itself many times and serves as a technique that complements traditional manufacturing processes such as milling. Electrical discharge machining is perfect for the production of difficult-to-make gears, mechanical components, and prototypes for quick turning. Remember that there are several types of electrical discharge machining which we write about below!
Types of Electrical Discharge Machining
Below we present several types of the electrical discharge machining method:
- Wire EDM - in this method, the electrode is a brass wire that comes out of the reel and is fed through the upper and lower diamond guide. In this case, CNC control is responsible for controlling the wire using a previously programmed path along which this wire moves.
- Sink EDM - this type is also referred to as "Plunge EDM" or "Ram EDM", in Sink EDM the electrode has the shape being machined, and the machine uses this shape for erosion of the reverse shape in the machined object. The above method is exceptionally precise and is used for burning cavities in a mold, which is then used to produce a huge amount of parts.
- Small hole EDM - In the case of small hole EDM, a small hollow electrode rotates around the spindle, similar to a drill. This type of EDM complements the wire and provides the ability to drill pilot holes in heat-treated materials and carbide.
Electrical discharge machining - why is it worth using?
Below we present the advantages that are associated with electrical discharge machining:
- It is used for creating complex shapes that would otherwise be difficult to achieve using conventional cutting tools.
- It is a great solution for cutting exceptionally hard and demanding as well as non-standard materials. It does this in an extremely precise manner.
- It has great prospects for machining very small objects, which in the case of using another method may be damaged as a result of pressing cutting tools on them.
- There is no contact between the tool and the object being machined. As a result, delicate areas and weak materials can be machined without distortion.
- The use of electrical discharge machining on objects leaves no burrs.
- After machining, there is no need to polish the object.
Disadvantages of electrical discharge machining
- Electrical discharge machining is a relatively slow solution.
- It takes a lot of time and resources to create electrodes for EDM Ram/Sink.
- Recreating sharp corners on the workpiece is difficult due to electrode wear.
How to work using electrical discharge machining?
We recommend following the steps below to achieve the best results with electrical discharge machining.
- If you have the opportunity, relax the surface finish. This allows for creating an element with fewer passes at a higher current intensity and improved material removal speed.
- Design or prepare the part so that the amount of material removed by EDM is relatively small. Use traditional machining techniques to remove most of the material through finishing operations performed by electrical discharge machining. This will help reduce production costs.
EDM machining can be used for processing fuel rods, mass production, and many other activities. It is also applicable in the production of delicate and small parts (even down to several dozen micrometers). Electric current forms the basis of the technology of machines that perform hole drilling so accurately that there is no need to polish the machined products afterwards. It is a great solution for machining difficult-to-cut materials.