Research On Laser Welding Technology Based On Galvanometer Scanning

Laser welding technology based on two galvanometer scanners has many advantages such as high welding speed, accurate location, convenient and flexibility operation as compared with the traditional laser welding technology with fixed optical path system. This technology has extensive application in materials joining areas in foreign countries. However, the research of the laser welding technology is in its preliminary stage in China. There are great gaps between our country's and foreign advanced laser welding technology both in theoretical and applied research. Therefore, it is important to carry out the research of the laser welding technology based on galvanometer scanning.In this paper, the experimental program was designed firstly, which include choosing welding materials and welding methods. Secondly, using metallographic microscope to check and measure the welding samples'feature and size .At last destroying tensile strength was measured in order to investigate the influence of welding factors on welding quality.Nd:YAG laser was used to weld the 304 stainless steel through galvanometer scanning spot and seal welding with single factor method. The influence of process parameters such as laser power, pulse width, pulse frequency, incidence angle and defocus amount on weld shaping and strength of the steel was amply studied. From the experimental results, it is found that as the laser incident angle increases, the bead width increases while the bead length decreases, as the pulse energy and pulse width increase, the surface diameter of the welding spot increases. The results indicate that the pulse energy has more effects on the surface diameter than the pulse width; As the current and pulse width increase, the weld width increases, and welding splash occur. Finally, the sample is oxidized and burned. As the pulse frequency increases, the overlapping rate of weld spot and weld width increase, the surface of weld beam is increasingly smooth, but rear surface of the sample is oxidized. The results indicate that the positive defocus amount is more easy to get smooth and beautiful weld than the negative defocus amount when the material is ultra-thin sheet. From the tensile test experiment results, it is found that the welding strength increased firstly and then decreased with one of the parameters increases. At last, this paper has researched the laser welding technology based on galvanometer scanning in application of batteries, Orthodontic Appliance and other fields.The mechanism of laser welding technology based on galvanometer scanning, the choice of welding parameters and the qualities of weld testing methods were comprehensively researched in this article. All the work done in this paper will provide theoretical and technological supports to the widespread application of laser welding technology based on galvanometer scanning.