Laser welding is one of the important aspects of the application of laser material processing technology. The welding process belongs to heat conduction type, that is, laser radiation heating the surface of the workpiece, the surface heat diffuses to the interior through heat conduction. By controlling the width, energy, peak power and repetition frequency of the laser pulse, the workpiece melts and forms a specific melting. Pool. Because of its unique advantages, it has been successfully applied to the welding of micro and small parts. Compared with other welding technologies, the main advantages of laser welding and laser soldering are fast speed, large depth and small deformation. It can be welded at room temperature or under special conditions. The welding equipment is simple. After laser focusing, the power density is high. When high power devices are welded, the aspect ratio can reach 5:1, and the maximum can reach 10:1. It can weld refractory materials such as titanium and quartz, and can weld heterosexual materials with good results. Moreover, it can weld two different materials, copper and tantalum, and the qualified rate is almost 100%. It can also be used for micro welding laser soldering. The laser beam can obtain very small spot after focusing, and can be positioned precisely. It can be applied to the assembly welding of micro and small components in mass automation production. For example, integrated circuit lead, watches hairspring, image tube electron gun assembly, etc. Because of the use of laser welding, not only the production efficiency is high, but also the heat-affected zone is small, and the solder joint is small. No pollution, greatly improving the quality of welding. It has great flexibility to implement non-contact long-distance welding in parts that are difficult to be welded. The application of optical fiber transmission technology in YAG laser technology has made laser welding technology more widely popularized and applied. Laser beam is easy to realize beam splitting according to time and space. It can process multi-beam and multi-station simultaneously, which provides conditions for more precise welding.
