The high-velocity electron beam when strikes the weld area of two metal pieces and very intense heat is generated which melts the metal and they fuse together to form a strong weld.The whole process is carried out in a vacuum chamber to prevent it from contamination.In 1958 he introduced the first practical EBW machine that was put into operation.The intensity of heat produced is so much that it melts the two metal pieces and fuse them together to form a strong weld.
There are two types of electron guns, the first one is self accelerated and the second one is work accelerated. In self accelerated gun, the acceleration of electron takes by applying a potential difference between cathode and anode. And in the work accelerated gun, the acceleration of the electron takes place by applying the potential difference between the cathode and workpiece. It accelerated the electrons under the influence of high potential difference. For high voltage equipment, the potential difference ranges from 70 kV to 150 kV and for small voltage equipment it ranges from 15 30 kV (iii) Grid Cup: It is used to control the electron beam. It stops the divergence of electrons produced by the cathode. It has applied with negative voltage with respect to the cathode. Focusing Unit: Tt consists of two parts a magnetic lens and a deflector coil. ![]() The extent of deflection can be varied by changing the amount of dc voltage across the deflector plate. The voltage ranges from 70-150 kV for high voltage equipment and 5-30 kV for small voltage equipment. ![]() The pressure ranges from 100 kPa for open atmosphere to 0.13-13 Pa for partial vacuum and 0.13 to 133 mPa for hard vacuum. The extent of scattering increases with the increase in the vacuum and this allows more penetration in the workpiece. The anode which is positively charged attracts the electron from the cup grid. And the deflector coil deflects the beam to the required weld area. As the high-velocity electron beam strikes the workpiece, intense heat is produced and it melts the metal of the two workpieces and fills the weld area.
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