A pulsating high- frequency electric current is applied between the tool point and the workpiece, causing sparks to jump the gap and vaporize small areas of the workpiece. Because no cutting forces are involved, light, delicate operations can be performed on thin workpieces. EDM can produce shapes unobtainable by any conventional machining process. Electrochemical Electrochemical machining also uses electrical energy to remove material. An electrolytic cell is created in an electrolyte medium, with the tool as the cathode and the workpiece as the anode. A high-amperage, low-voltage current is used to dissolve the metal and to remove it from the workpiece, which must be electrically conductive. A wide variety of operations can be performed by ECM; these operations include etching, marking, hole making, and milling. EUltrasonic Ultrasonic machining employs high-frequency, low-amplitude vibrations to create holes and other cavities.
A relatively soft tool is shaped as desired and vibrated against the workpiece while a mixture of fine abrasive and water flows between them. The friction of the abrasive particles gradually cuts the workpiece. Materials such as hardened steel, carbides, rubies, quartz, diamonds, and glass can easily be machined by USM. FElectron Beam In electron-beam machining , electrons are accelerated to a velocity nearly three-fourths that of light. The process is performed in a vacuum chamber to reduce the scattering of electrons by gas molecules in the atmosphere. The stream of electrons is directed against a precisely limited area of the workpiece; on impact, the kinetic energy of the electrons is converted into thermal energy that melts and vaporizes the material to be removed, forming holes or cuts.
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