Potential of laser welding gun technology

1. introduction: The increasing requirements of the automotive production in terms of the flexibilization of component-geometries and materials as well as the reduction of the number of sub-processes, pose a special challenge for joining technologies. The laser welding technology, which is characterized by a high material-flexibility and very fast processing times, is one technology which have a high potential to comply this requirements in a special way. Especially the development of laser-welding-guns and laser-picker-systems, which combines the advantages of a conventional laser welding process and the advantages of a resistance spot welding process, increases the potential of laser technologies for the flexibilization in a special way.2. results The aim of the investigations was the development of technologies which are suitable for the manufacturing of seams at the overlap joint of zinc layered steel, aluminum (6000 series) and steel-aluminum multimaterial joints. For this purpose the process influencing parameters and factors - like the realization of the gas emission during the welding of zinc layered steels, - the prevention of heat introduced cracks by the welding of aluminum of 6000 series, or - the growing of brittle FeAl-layers during the welding of steel-aluminum joints have been detected and analyzed. Based on these results, proven technologies for the solving of the named problems for conventional laser welding technologies have been selected and investigated with the regard to the transferability to the new laser-welding-gun systems. To achieve these objectives it was necessary to optimize selected technologies to the requirements of the new laser welding systems. For the verification of the suitability of the technologies, samples made of different materials, thicknesses and combinations were welded and have been analyzed according to the quality and strength properties.3. results By the development and adaptation of technologies for the joining of steel, aluminum and steel-aluminum joints, adapted to the conditions of the welding guns, it has been possible to provide the proof of suitable for laser welding guns.