Electron beam technology offers the perfect prerequisites for welding conductive metals such as copper and nickel or lightweight metals such as aluminum and aluminum alloys with very narrow seams or for hardening components.
Electron beam welding process parameters.
The current level ranges from 50 to100 ma.
Electron beam eb welding is a fusion welding process whereby electrons are generated by an electron gun and accelerated to high speeds using electrical fields.
This allows for a very high volumetric power density which can reach values of the order 10 5 10 7 w mm 3.
This high speed stream of electrons is tightly focused using magnetic fields and applied to the materials to be joined.
The higher the vacuum the less amount of contamination and residual gasses will be present when the welding occurs.
Prior welding the specimens were fixed by clamps which pressing the four corners of the plates as shown in fig.
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Values of power density in the crossover focus of the beam can be as high as 10 4 10 6 w mm 2.
The vacuum level makes a difference in the quality of the weld.
The power supply used in the electron beam welding process is dc power supply sources.
Unlike the laser beam however the electron beam process utilises a vacuum chamber in which is generated a high energy density beam of electrons of the order of 0 25 2 5 mm in diameter fig.
The welding parameters selected in this experiment using the accelerating voltage of 55 kv welding speed of 6 7 mm s and the beam current ranged from 12 ma to 28 ma.
The welded assembly exhibited a minimum amount of distortion but a better understanding of the effects of several key welding parameters on the structural integrity of the weld was required.
Shallow penetration depths in the order of hundredths of a millimeter.
Electron beam welding is like laser welding a power beam process ideally suited to the welding of close square joints in a single pass.
This parameter unique to the eb process deflects the beam at a rate of a few hundred hertz in a pattern such as circle or arrow head figure 5.
The voltage ranges from 70 150 kv for high voltage equipment and 5 30 kv for small voltage equipment.
Electron beam welding was used for joining al6061 t6 precision machined cylindrical sections.
Electron beam welding must occur in a vacuum because air molecules interfere with the propagation of the electron beam.
One of the parameters provided by the eb process is the capability to change dynamic movement of the molten material by influencing the size of the key hole.
