10-04-2017, 07:23 PM
Electro Discharge Machining (EDM) is an electro-thermal non-traditional machining process, where electrical energy is used to generate electrical spark and material removal mainly occurs due to thermal energy of the spark. EDM is mainly used to machine difficult-to-machine materials and high strength temperature resistant alloys. EDM can be used to machine difficult geometries in small batches or even on job-shop basis. Work material to be machined by EDM has to be electrically conductive. EDM is sometimes called "spark machining" because it removes metal by producing a rapid series of repetitive electrical discharges. Electrical discharge machining Is a manufacturing process whereby a wanted shape of an object, called workpiece, is obtained using electrical discharges (sparks). The material removal from the workpiece occurs by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric liquid and subject to an electric voltage These electrical discharges are passed between an electrode and the piece of metal being machined. The small amount of material that is removed from the workpiece is flushed away with a continuously flowing fluid. The repetitive discharges create a set of successively deeper craters in the work piece until the final shape is produced.
There are two primary EDM methods: ram EDM and wire EDM. The primary difference between the two involves the electrode that is used to perform the machining. In a typical ram EDM application, a graphite electrode is machined with traditional tools. The now specially-shaped electrode is connected to the power source, attached to a ram, and slowly fed into the workpiece. The entire machining operation is usually performed while submerged in a fluid bath. The fluid serves the following three purposes:
flushes material away
serves as a coolant to minimize the heat affected zone (thereby preventing potential damage to the workpiece)
acts as a conductor for the current to pass between the electrode and the workpiece.
read more
http://nptel.iitm.accourses/Webcourse-co.../LM-39.pdf
http://en.wikipediawiki/Electrical_discharge_machining
There are two primary EDM methods: ram EDM and wire EDM. The primary difference between the two involves the electrode that is used to perform the machining. In a typical ram EDM application, a graphite electrode is machined with traditional tools. The now specially-shaped electrode is connected to the power source, attached to a ram, and slowly fed into the workpiece. The entire machining operation is usually performed while submerged in a fluid bath. The fluid serves the following three purposes:
flushes material away
serves as a coolant to minimize the heat affected zone (thereby preventing potential damage to the workpiece)
acts as a conductor for the current to pass between the electrode and the workpiece.
read more
http://nptel.iitm.accourses/Webcourse-co.../LM-39.pdf
http://en.wikipediawiki/Electrical_discharge_machining