In our high-tech age, refractory, heat-resistant, anti-corrosion and radiation-resistant materials are becoming more and more common, for which special techniques are required for welding. Such as electron beam welding, in which the temperature of the active working zone reaches a thousand times higher than with traditional methods. Ultra-high temperatures in this type of welding are achieved due to photons or electrons moving in a vacuum chamber at a speed of about 165,000 km / s. When bombarding metal at such an incredible speed, the kinetic energy of elementary particles is converted into heat, which melts the metal.
Electron-beam welding is carried out in a special chamber, from which air is previously pumped out. An airless space is created so that the electrons do not waste their energy on the ionization of the gas mixture and to obtain ideal metal seams without foreign inclusions. The cathode beam setup, as this vacuum chamber is called, is equipped with a special magnetic lens designed to form a directed electron flow and effectively control it. It also has a loading hatch for feeding parts to be welded.
Electron beam welding is done with low voltage alternating current. It flows through a special focusing element (lens), where the cathode and anode are located, and, thus, an electron flow with specified characteristics is created. In low-power installations, a tungsten or tantalum coil is used as the cathode. And if the technological process and the individual properties of the materials being welded require more power, then cathodes made of cermet or lanthanum hexaboride, which have an increased ability to emit free electrons, are already used.
Depending on the design features of the installation, electron beam welding can be performed by moving the material being welded perpendicular to the fixed beam, or vice versa, the beam can move relative to the fixed part. Also, the design of some installations provides for the presence of special deflecting devices, which gives more opportunities for obtaining figured seams.
This type of welding is widely used in welding high-strength alloy steels and titanium-based alloys, as well as metals such as molybdenum, tantalum, niobium,tungsten, zirconium, beryllium. For precision machining and welding of various micro parts. It is used in industries such as rocket science, nuclear power, precision instrumentation, microelectronics, and many others.
Along with electron beam technology, laser welding is also widespread. The equipment for this type of welding is an optical laser generator, which is an ultra-modern source of coherent radiation. The fundamental difference between laser welding and the electron beam method is that it does not require vacuum chambers. The welding process using laser technology is carried out in an air environment or in conditions of saturation of the chamber with special protective gases - carbon dioxide, argon and helium.
