Electron beam technology
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Free electrons in vacuum can be influenced by electric and magnetic fields as to form a fine beam. At the spot of collision of the beam with the particles of the solid-state matter, most portion of the kinetic energy of electrons is transferred into heat. The main advantage of this method is the possibility of very fast local heating, which can be precisely electronically (computer) controlled. The high concentration of power in a small volume of matter, which can be reached in this way results in very fast increase of temperature in the spot of impact causing the melting or even evaporation of any material, depending on working conditions. This makes the electron beam an excellent tool in many applications.
- 1 Electron beam furnace
- 2 Electron beam welding
- 3 Electron beam surface treatment
- 4 Electron beam additive manufacturing
- 5 Electron beam machining
- 6 Electron beam lithography
- 7 Electron beam metal powder production
- 8 Electron beam physical vapor deposition
- 9 Electron beam curing
- 10 Electron microscope
- 11 References
Electron beam furnace
Any material can be melted by an electron beam in vacuum. This source of heat is absolutely clean, as well as the vacuum environment, so the purest materials can be produced in electron beam vacuum furnaces. For the production or refinement of rare and refractory metals the vacuum furnaces are of smaller volume, but for steels large furnaces with capacity in metric tons and electron beam power of megawatts are operated in industrialized countries.
Electron beam welding
The above mentioned specific advantages of electron beam heating find the widest use in welding applications. Since the beginning of electron beam welding in industrial scale (end of 1950s) a countless number of electron beam welders with working vacuum chambers volume ranging from a few liters up to hundreds cubic meters, provided with electron guns with the power up to 100 kW have been designed and are used world wide.
Electron beam surface treatment
The modern electron beam welders are usually provided with computer controlled deflection system, which can position the beam very fast and accurate over the selected area of the work-piece surface. Thanks to the high speed of heating, only a thin surface layer of the material is influenced, e.g. for "hardened", annealing, tempering, texturing, polishing(with argon gas present) etc. If the electron beam is used to cut a shallow trough in the surface, then repeatedly moving horizontally along the trough at high speeds it creates a small pile of ejected melted metal at the end of the trough, Upon repetition spike structures can be created up to a millimeter high. These can aid bonding between different materials and modify surface roughness of the metal.
Electron beam additive manufacturing
Additive manufacturing is the process of joining materials to make objects from 3D model data, usually by melting powder material layer upon layer. Melting in vacuum by a computer controlled scanning electron beam is very advantageous. Electron beam direct manufacturing (DM) is the first commercially available, large-scale, fully programmable means of achieving near net shape parts.
Electron beam machining
Electron-beam machining is a process where high-velocity electrons concentrated into a narrow beam with very high planar power density in the focus cross-section are directed toward the work piece, creating heat and vaporizing the material. Electron beam machining can be used for very accurate cutting or boring of a wide variety of metals. Surface finish is better and kerf width is narrower than those for other thermal cutting processes, but because the equipment acquisition costs are very high, the use of this technology is therefore limited economically.
Electron beam lithography
Electron lithograph is a device in which a very fine electron beam is used to create micro-structures in the resist that can subsequently be transferred to the substrate material, often by etching. It was developed for manufacturing integrated circuits, and is also used for creating nanotechnology architectures. Electron beams with diameter ranging from 2 up to hundreds of nanometers are used in electron lithographs.
The form of maskless lithography has found wide usage in photomask-making used in photolithography, low-volume production of semiconductor components, and research & development. The electron lithograph is also used to produce computer-generated holograms (CGH).
Electron beam metal powder production
The source billet metal is melted by an electron beam while being spun vigorously; powder is produced as the metal cools while flying off the metal bar.
Electron beam physical vapor deposition
Electron beam curing
Method of curing paints and inks specially devised for this process, so avoiding the need for traditional solvent usage in curing paints and inks. These paints give a similar finish to the traditional solvent evaporation process, but it is achieved through a polymerization process.
An electron microscope uses a beam of electrons to illuminate a specimen and produce a magnified image. Two common types of electron microscope are the scanning electron microscope (SEM) and transmission electron microscope (TEM).
- Schultz, H.: Electron beam welding, Abington Publishing
- Von Dobeneck, D.: Electron Beam Welding – Examples of 30 Years of Job-Shop Experience
- www.ebt.isibrno: Electron beam welding (in Czech and/or English)
- Visser, A.: Werkstoffabtrag durch Elektronen-und Photonenstrahlen; Verlag <Technische Rundschau>, Blaue Reihe, Heft 104