EDM Machining Process & Techniques
(Electrical Discharge Machining)
A machining method typically used for hard metals, Electrical Discharge Machining (commonly known as "EDM Machining") makes it possible to work with metals for which traditional machining techniques are ineffective. An important point to remember with EDM Machining is that it will only work with materials that are electrically conductive.
With good EDM Machining equipment it is possible to cut small odd-shaped angles, detailed contours or cavities in hardened steel as well as exotic metals like titanium, hastelloy, kovar, inconel, and carbide.
The EDM Process is commonly used in the Tool and Die industry for mold-making, however in recent years EDM has become a integral part for making prototype and production parts. This is seen in the aerospace and electronics industries where production quantities remain low.
The Wire EDM / Spark EDM Process
Wire EDM Machining (also known as Spark EDM) is an electro thermal production process in which a thin single-strand metal wire (usually brass) in conjunction with de-ionized water (used to conduct electricity) allows the wire to cut through metal by the use of heat from electrical sparks. Due to the inherent properties of the process, wire EDM can easily machine complex parts and precision components out of hard conductive materials.
The Sinker EDM Machining Process
In the Sinker EDM Machining process, two metal parts submerged in an insulating liquid are connected to a source of current which is switched on and off automatically depending on the parameters set on the controller. When the current is switched on, an electric tension is created between the two metal parts. If the two parts are brought together to within a fraction of an inch, the electrical tension is discharged and a spark jumps across. Where it strikes, the metal is heated up so much that it melts.
The History of Electrical Discharge Machining
The history of EDM Machining Techniques goes as far back as the 1770s when it was discovered by an English Scientist. However, Electrical Discharge Machining was not fully taken advantage of until 1943 when Russian scientists learned how the erosive effects of the technique could be controlled and used for machining purposes.