Table of Contents
- Understanding The EDM Process
- Benefits And Applications of Wire EDM
- Unique Advantages of Working with Wire EDM
Electrical discharge machining (EDM) is a manufacturing process that implements electrical sparks to form a metal shape. Because of these sparks, EDM is also sometimes referred to as spark machining. In this process, the desired shape is cut from the metal when current discharges, or sparks, occur between two electrodes; where the sparking occurs, cuts are made into the metal, creating the desired shape and detaching it from the metal sheet.
There are two main types of EDM — wire and sinker — and several other less common methods, but this article will be focusing on wire EDM. Wire EDM uses a wire as the tool electrode. The wire is wound between two spools and, when in motion, the active part of the wire continually switches — preventing the material from eroding from the wire itself.
UNDERSTANDING THE EDM PROCESS
During the EDM process, a metal part is placed into dielectric fluid, and a wire is fed through the submerged metal component. An electric current is sent through the part to create the sparks that will ultimately help form the desired shape of the component.
When the distance separating the electrodes narrows, it increases the intensity of the electric field, and thus increases the strength of the dielectric fluid. The current more easily passes between the two electrodes under these conditions, leading to the separation of the component from the metal sheet with each spark.
After the currents have passed through and the desired shape has been achieved, manufacturers will sometimes perform a process called “flushing,” using a dielectric liquid to help remove any leftover material or waste from the finished product.
BENEFITS AND APPLICATIONS OF WIRE EDM
The wire EDM machine, also known as a “cheese cutter,” offers several unique advantages, making it a popular choice for manufacturers across a range of different industries.
Wire EDM machines are able to carefully remove excess material without exerting a strong cutting force. The process is often automated, meaning it has less chance of causing damage to the workpiece itself. And because wire EDM machines can accommodate hard materials, there is no need for secondary, post-machining thermal treatments. As a result, there is little to no heat stress placed on the shaped part, and less chance that the surface of the part will become distorted.
Wire EDM is most commonly used in mold and die manufacturing processes, particularly for extrusion dies and blanking punches. EDM can be used in everything from prototypes to full production runs, and is most often used to manufacture metal components and tools. The process is best suited for applications requiring low levels of residual stress.
EDM is most commonly used to manufacture parts and components for the automotive, aerospace, and electronics industries.