EDM is an original and highly accurate machining process in which a component made of a conductive material has characteristics resulting from controlled material erosion by electrical discharges (sparks). In the basic assumption, the electroerosion treatment is applied to two electrodes. When the field strength between the two electrodes is high enough, the dielectric breaks down, the electric current flows and the material is removed from both electrodes. It is worth emphasizing that the current flow between the electrodes is not constant. Why use electrical discharge machining? What are its advantages and what should be noted? We’re writing about this below!
Electrical Discharge Machining is a great method
An increasing number of entities use EDM (electrical discharge machining). It is mainly used in industries that require precise parts. This solution has proven itself many times and serves as a technique that complements traditional production processes such as milling. Electrical discharge machining is ideal for manufacturing difficult-to-make gears, mechanical components and prototypes for high-speed turning. Let us remember that there are several types of electrical discharge machining, which we are writing about below!
Types of Electrical Discharge Machining
Wire edm cutting is done through electrically conductive materials. Wire edm projects are created by the edm machine and metal wire. Here are a few different types of electrical discharge machining methods that are currently in use:
- Wire EDM – in this method, the electrode is a brass wire that exits the spool and is fed through the top and bottom diamond guides. The CNC control in this case is responsible for controlling the wire using a pre-programmed path along which the wire moves.
- Sink EDM – this type also referred to as „Plunge EDM” or „Ram EDM”, in Sink EDM the electrode is machined in a specific way and the machine uses this shape to erode the reverse shape in the workpiece. This method is extremely precise and is used to burn cavities in a form which is then used to produce a large quantity of parts.
- EDM small hole drilling – for EDM small hole drilling, a small hollow electrode rotates around the spindle, just like a drill. This type of EDM complements the wire and provides the ability to drill pilot holes in heat-treated materials and carbide.
Wire EDM machining – why is it worth using?
The following are the advantages that are associated with wire EDM machining:
- Creates complex shapes that would otherwise be difficult to perform with conventional cutting tools.
- It is a great solution for cutting extremely hard, demanding and non-template materials. This is done in an extremely precise way.
- It has great prospects for machining very small workpieces, which other methods can damaged by pressing them with cutting tools.
- There is no contact between the tool and the workpiece. For this reason, delicate areas and weak materials can be processed without distortion.
- The use of electrical discharge machining on workpieces will not leave jagged edges.
- No polishing of the workpiece is required after processing.
Disadvantages of EDM
- Electrical discharge machining is a relatively slow solution.
- It takes a lot of time and money to create electrodes for EDM Ram/Sink.
- It is difficult to reproduce sharp corners on the workpiece due to the wear of the electrode.
How to work using EDM?
We recommend that you follow the steps below to obtain the best results in wire cutting.
1) If possible, loosen the surface finish. You can then create an element with fewer passes at higher current and improved material removal speed.
2) 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 and finish with electrical discharge machining. This will reduce production costs.
3) If the holes are to be enlarged or converted using electrical discharge machining, then through holes are preferred over blind holes. This makes it easier for the dielectric fluid to pass through the work area.
4) Establish a cleaning procedure in case of galvanic corrosion.