Electron beam welding is a welding technique where a beam of high-velocity electrons are applied to the materials that are being welded. The materials then melt as the kinetic energy of the electrons produces heat, and any filler metal that happens to be used also melts to create the weld. This type of welding is most commonly performed in a vacuum to prevent the dispersion of the electron beam that is used. This process of welding was created in 1958 by Karl-Heinz Steigerwald.
While this process is a favorite to weld certain metals, it cannot be used on all metals. Electron beam welding cannot be used to weld metals that have a high vapor pressure at their melting temperature. These metals include zinc, cadmium, magnesium and virtually all non-metals.
The process of electron beam welding can be used to create strong solid welds on materials that can be welded in a vacuum. But no welding process is perfect, there are problems and limitations to all welding techniques and electron beam welding is no different. The materials that are welded using electron beam welding tend to shrink during the cooling process which may lead to cracking, shape changes, and deformities in the finished product. The emergence of cracks in a finished weld can be very dangerous. They may lead to the joint becoming brittle and eventually breaking. These limitations should be taken into consideration before using electron beam welding.
The equipment used in electron beam welding is very different to the equipment that many welders use on a day to day basis. This technique requires the use of an electron gun which creates the electron beam, a vacuum chamber where the welding takes place, a work piece manipulator which is used to position the materials that are to be welded, and electronics that are used to monitor and control the welding process.
Electron beam welding is a process that is primarily used in an industrial setting and is not a technique that many welders will be exposed to through the course of their career. It is capable of producing micro welds on small objects and can perform deep welds up to 300mm when needed. Depending on the capacity in which the process is used, the vacuum chambers used can range in size from a few liters to several hundred cubic meters. This was a groundbreaking discovery when it was first developed and new uses continue to be found as technology advances.
Reference: http://en.wikipedia.org/wiki/Electron_beam_welding
