Electron Beam Welding Process Parameters

Prior welding the specimens were fixed by clamps which pressing the four corners of the plates as shown in fig.

Electron beam welding process parameters.

The power supply used in the electron beam welding process is dc power supply sources. The higher the vacuum the less amount of contamination and residual gasses will be present when the welding occurs. This article throws light upon the four main process variables in electron beam welding ebw. This high speed stream of electrons is tightly focused using magnetic fields and applied to the materials to be joined.

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. 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. Electron beam welding must occur in a vacuum because air molecules interfere with the propagation of the electron beam. Download high res image 187kb.

Short cycle times a high level of automation and a low rejection rate are key parameters in the automotive industry. Electron beam welding is like laser welding a power beam process ideally suited to the welding of close square joints in a single pass. 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. The vacuum level makes a difference in the quality of the weld.

The voltage ranges from 70 150 kv for high voltage equipment and 5 30 kv for small voltage equipment. 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 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. Shallow penetration depths in the order of hundredths of a millimeter.

This allows for a very high volumetric power density which can reach values of the order 10 5 10 7 w mm 3. The beam of electrons creates kinetic heat as it impacts with the workpieces causing them to melt and bond together. 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. Values of power density in the crossover focus of the beam can be as high as 10 4 10 6 w mm 2.

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.