Electron Beam Machining

    In electron-beam machining (EBM), electrons are accelerated to a velocity nearly three-fourths that of light (~200,000 km/sec). The process is performed in a vacuum chamber to reduce the scattering of electrons by gas molecules in the atmosphere. The electron beam is aimed using magnets to deflect the stream of electrons and is focused using an electromagnetic lens. 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.

Typical applications are annealing, welding, and metal removal. A hole in a sheet 1.25 mm thick up to 125 micro m diameter can be cut almost instantly with a taper of 2 to 4 degrees. EBM equipment is commonly used by the electronics industry to aid in the etching of circuits in microprocessors.


(Kaynak: EngineersHandbook)