Improvement of energy deposition in absorber-free laser welding through quasi-simultaneous irradiation
| Autor: | Christoph Engelmann, Alexander Olowinsky, Viktor Mamuschkin |
|---|---|
| Přispěvatelé: | Publica |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0209 industrial biotechnology
Heat-affected zone Materials science 010308 nuclear & particles physics business.industry Laser beam welding 02 engineering and technology Welding Physics and Astronomy(all) Electric resistance welding quasi-simultaneous 01 natural sciences polymer welding law.invention Fusion welding 020901 industrial engineering & automation Optics law 0103 physical sciences absorber-free Cold welding Absorption (electromagnetic radiation) business Thulium fiber laser Upset welding |
| Popis: | Laser transmission welding is usually known to put little thermal stress on the joining partners, indicated by a small heat affected zone (HAZ). However, this only applies when the joining partners have adapted optical properties. When it comes to welding of optically equal thermoplastics without absorbers, the main issue is the HAZ extending far from the interface. To enable welding without absorbers, lasers emitting within the polymer's intrinsic absorption bands are used. So far, different beam shaping approaches have already been investigated to achieve a selective energy deposition at the interface but, with little success to date. The approach presented in this paper is irradiating the welding path quasi-simultaneously to exploit the poor heat conductivity of polymers. Therefore, the influence of the irradiation regime on the seam formation is considered in detail. Another aspect investigated is the length of the irradiated contour which is a crucial factor in quasi-simultaneous welding. The results show that the energy deposition can be significantly improved when the welding contour length does not exceed a critical length determined by the capability of the welding system. However, by welding in segments the approach can also be applied to longer contours without any noticeable loss in welding time. The ideal irradiation regime obtained in the trials corresponds to an effective welding speed of 37mm/s and reduces the vertical extent of the HAZ by 30%. |
| Databáze: | OpenAIRE |
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