So, you want to know what EDM is and how it works. That’s great! This subject can help you better understand modern manufacturing and why some products are more expensive than others. The truth is that EDM can be used to produce almost any kind of part, including ones that would be impossible with conventional machining techniques.
EDM machines use an electrode to generate spark discharges
Electrical Discharge Machines use an electrode to generate spark discharges between themselves and the workpiece. The electrode can be made of many different materials, but it must be conductive to electricity to send a current through the machined metal. The machine will generate an electrical charge on one end of the electrode, which travels through that part of the machine and creates an electric field around your metal piece.
The resulting discharge creates heat inside any conductive material like iron or steel when struck by enough voltage (approximately 5kV). This raises temperatures quickly enough for material softening without melting due to localized heating effects outside its bulk area.
The main advantages of EDM are speed and precision.
A few advantages to EDM make it very attractive as a manufacturing process. First, the speed of production is faster than any other machining method. Second, EDM can be used to produce parts made of any material-even soft metals such as aluminum and magnesium. If you need to make complex geometries with tight tolerances in your part, then you will find an EDM machine can do this more easily than any other method.
Finally, because there is no cutting involved (only removal), there is no debris produced by the process-this means fewer clean-up steps after machining has finished.
No force is applied to the workpiece during processing.
You might think EDM is a grinding or milling process, but it’s not. Grinding and milling are ways of removing material from a workpiece using a cutting tool. In EDM, no force is applied to the workpiece during processing-the electrical discharge consummates its task without any physical contact between itself and the removed material.
EDM is also not a grinding or milling process because it doesn’t remove material by friction (the abrasive wear caused by two surfaces rubbing against one another). There’s no abrasive involved in any EDM operation whatsoever!
Two types of fluid dielectrics are used in EDM: oil and water-based.
Two types of fluid dielectrics are used in EDM: oil-based and water-based. Oil-based fluids are excellent at removing metal chips and have good lubricating properties, but they suffer from poor electrical conductivity. Water-based fluids offer superior electrical conductivity but tend to clog up the electrode with metal sludge over time. Both types need filtration systems to remove the chips and sludge from their electrodes so they continue performing at their best levels.
The spark discharge machining process can make complicated shapes that other processes cannot reach.
EDM is a subtractive process. EDM machines use an electrical current to cut material by spark discharge. The spark discharge machining process can make complicated shapes that other processes cannot reach.
Because it’s an electrically charged or “live” process, EDM has some important safety considerations that you should be aware of before operating one at your facility:
- All personnel must stay at least 10 feet away from the EDM machine during all operations and for 30 minutes after the cutting has ended (this includes both operators and service/support personnel).
- All electrical connections must be shielded when possible; if not possible, grounding straps must be used when connecting equipment to power sources outside the machine housing.
- All external circuits must have circuit breakers installed and rated appropriately (for example, 125 amps maximum for a 5-axis machine).
Conclusion
Many think EDM is just for jewelry and small art pieces, but it can be used on any material. It has many advantages over other processes, like cutting speed and precision.
There are also some disadvantages to consider when using this method, such as using water- or oil-based dielectrics instead of traditional cutting fluids like water- or oil-based dielectrics. This article has given you some information about EDM machining, so go out there and give it a try.
