Electrical Discharge Machine (EDM) is a non-traditional method to remove material from a workpiece through Electric Discharge.
The Encyclopedia Britannica defines EDM as “EDMinvolves the direction of high-frequency electrical spark discharges from a graphite or soft metal tool, which serves as an electrode, to disintegrate electrically conductive materials such as hardened steel or carbide or any conducting material.”
EDM comes in handy when the traditional cutting tools like grinders and end mills don’t provide the efficiency and accuracy in creating parts with particular shapes or angles. There are two types of EDM –EDM (traditional), and Wire Cut EDM.
Let’s understand them both in detail.
EDM
This is primarily a conventional process. It is also known as ram EDM, die sinking, sinker EDM, volume EDM, and cavity-type EDM. It deploys an electrode tool that has a profile match with the intended and distinctive shape. The electrode and workpiece or job and in between insulating fluid to perform a process.
EDM can create various blind shapes and surface curvatures. It can sink deep into the material that requires cutting or shape. It creates a negative impression of its shape, which results in the formation of a mold.
EDM is useful when you want to work with a conductive material like any metal. Since it exerts minimal force, you can even use it for fragile materials and delicate shapes.
EDM gives a 3D profile to the die. It can produce blind features like holes and cavities that are closed in the bottom end.
Wire Cut EDM
The wire-cut EDM machine is the modern version of traditional EDM. It uses a wire to discharge the electric current and transmit it to the electrically conductive workpiece.
The wire constantly moves between the two fixed pulleys while the workpiece gets the friction against the wire. It generates a spark between the wire and the workpiece.
Wire cut EDM is useful when you want an even, smooth and uninterrupted form. It also comes in handy when looking for high accuracy in sample preparation, profile cutting, and parting or separating off.
Since it has a simple geometry, it is preferred for 2D profiles. However, it is unsuitable for applications that need-blind features.
Which is Better – EDM or Wire Cut EDM
There is no comparison as their use depends on the purpose and type of application. However, the popularity of wire cut EDM has grown over the years owing to its ease of production, low maintenance, and speed. EDM is also less costly than EDM. When the time is of the essence, wire cut EDM is very useful.
This content was originally published on the Phillips Corp website.
