The Russian satellite maker, NPO Lavochkin, has entered into an agreement with local and foreign experts for the production of a new light-laser welding system that uses strong polychromatic energy sources. From a local perspective, the Sarov-based All-Russia Research Institute of Experimental Physics is providing its expertise, while Professor Antonio Lapucci of the Italian Institute of Applied Optics in Florence and Professor Ulrich Delthey, the Director of the German Welding Institute in Aachen, are offering their know-how. The project will effectively help players to overcome any problems that once plagued the laser welding industry.
With funding provided by the International Science and Technology Centre, the project consists of a complex involving Nd-YAG-laser and a special light module. The former is a neodymium-yttrium aluminium garnet laser that carries out the spot weld, while the latter, whose spectrum can be changed, is a strong light source.
|The new approach is expected to raise industry competitiveness.
To ensure automatic welding according to a preset programme, the complex has been equipped with the necessary materials and software. An initial experimental version of the complex has already been developed and is being tested by NPO Lavochkin researchers.
The method basically centres on the use of the second light source for radiation, as it can heat a weld area and its surroundings instantaneously. Temperatures can top the 1,000-degree mark. The experts claim that this method eliminates the need to temper ready products and results in fewer defects forming under the welding of cold parts.
Welders are aware that proper heating of parts leads to better weld-join quality. However, for some time, welders have questioned how parts can be heated rapidly and successfully if they are made from different solid materials, like glass, or from different alloys, like invar, when their dimensions cannot change despite being heated. The concern was how to heat parts to high temperatures without damaging them.
Enter Valentin Sysoev, the head of the Analytical Department, who along with his colleagues offered a solution to the problem. According to Sysoev, using the beam of a powerful lamp on the surface to be welded would heat the object to the right temperature. The researchers assert that what is needed is for energy sources to be used to heat surfaces, not weld them. The spot of the weld and the surrounding area will be smoother when the temperature drops, they say. The end result is improved weld quality.
Overall, the new method will prove to be competitive, yet effective for all future laser welding processes, without compromising on quality.