Fusion welding: fusion welding other than arc welding

Laser welding

Laser welding is a process that concentrates light of frequencies that display high directivity and convergence with a lens and uses laser beams with extremely high energy density as a heat source. It allows weld penetration that is relatively narrow compared with the depth. This technique using the directivity and convergence of a laser beam is also used for welding in the tailored blank (TB) process or for cutting or working thin plates.

Laser welding can be broadly divided into two types depending on the method used to produce the light that serves as the welding energy. Gas laser welding uses carbon dioxide (CO2) or other gases to produce light (example: CO2 laser welding). For solid state lasers, YAG laser welding uses mineral ores such as yttrium, aluminum and garnet.

Gas laser
Gas laser
Solid-state laser
Solid-state laser

Electron beam welding

Electron beam welding uses the heat emitted when an electron beam is generated in vacuum. When a cathode in vacuum is heated by filament, it emits electrons. The emitted electrons are accelerated by voltage and converged by an electromagnetic coil, and generate high heat energy when they strike the base material. Electron beam welding uses this heat for welding.
The beam spot diameter of typical electron beam welding machines is approximately 0.2 mm. The energy density of the electron beam is about 1,000 times that obtained with an arc. The heat applied to the area around the weld is low, which allows welding with less distortion. Controlling the output of the electron beam enables the adjustment of penetration. This method is applicable to a wide variety of base materials from thick to thin plates. It can also be used to weld metals with high melting points (such as tungsten) as well as active metals that have a chance of oxidation during welding (such as titanium).
Potential applications are ship's shell plates, bridges, storage tanks, aircraft parts and electronic components.

Among electronic components, sealing of crystal oscillators that must be joined in vacuum is processed with electron beam sealing, which performs vacuum brazing sealing by melting the filler material between the metal lid and ceramic package through the heat conduction induced by the electron beam.

Electron beam welding

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