Laser welding: principle of operation and advantages

The joining of metals can be done in different ways. The most reliable and progressive way to obtain permanent joints of different products is laser welding. Thanks to this technology, it is possible not only to achieve great accuracy and accuracy, but also to connect materials having a high melting point or high thermal conductivity. A short, controlled melting period and a small amount of melt enable welding even those parts for which conventional methods are not at all suitable.

Technology features

Laser welding is characterized by the fact that the laser beam makes it possible to provide a high concentration of energy at a point whose diameter does not exceed several micrometers. The power level reaches 10 ^ 8 W / cm2, which is much more than gives, for example, the arc. According to the concentration of energy, laser welding can only be compared with an electron beam (its power is about 10 ^ bW / cm2). But if the latter can only be used in a vacuum chamber, laser welding can be carried out in a medium with some protective gas (CO ₂ , He, Ar) or simply in air. With regard to control, it is implemented with the help of an optical system. Laser welding is performed in a fairly wide range of modes, and this provides a high-performance process of joining all kinds of materials, the thickness of which starts from several micrometers and reaches several tens of millimeters. Despite the fact that this process is very complicated and there is not yet a universal theoretical model that could describe it in its entirety, it is widely used in practice, and for good reasons.

What is good about laser welding of metals

Among the undoubted advantages of this method include the following:

1. High performance of this technology in comparison with other methods.
2. A small zone of thermal impact, which is limited to only one laser diameter. This makes it possible to obtain greater technological strength and ductility of the joint.
3. Easy management and the ability to change the processing program.
4. Ecological compatibility. Modern laser welding machine allows to do without auxiliary welding materials and fluxes.
5. The possibility of a qualitative connection of dissimilar metals.
6. It is very often possible to avoid the use of filler materials.
7. The possibility of welding in difficult places for access.

For welding of metal parts, gas and solid-state lasers of both continuous and periodic action are used. The application of the described technology directly depends on the capacity of the installations. So, lasers, whose power lies within 100-500 W, have long been used for welding small components, for example, electronic blocks or medical devices. And installations capable of concentrating a higher level of energy (in the kilowatt range) are often used together with robots and fiber optics. They are almost indispensable in the automotive, mechanical engineering, shipbuilding and other industries.