In the production of vehicle bodies, laser beam brazing has long secured for itself pride of place. However, the increased use of hot-dip galvanized sheets has of late led to problems: the number of micro splashes and wavelets has been growing, requiring a reduction in the process speed. With a variable multi-spot module, in which side-spots are positioned in front of the main spot, Laserline has developed a groundbreaking solution: the pre-spots ablate the galvanizing at the brazing seam and thus calm the brazing process, which could then be carried out at the normal speed. This process is rated as a trend-setter.
When still galvanized sheets (that means electrolyte-supported) are processed - we also talk about “elo-zinc” - for brazing diode lasers with a classical single spot are sufficient. Here, the beam source is mostly integrated into special brazing robots. Thanks to the calm molten pools created by diode lasers, melting of the typical brazing solders based on silver or whitish silver poses no problem at all. Well-designed seams with high quality are the end result.
In a process comparison between a 4 kW YAG and a 6 kW diode laser during the production of the VW Touran in Wolfsburg, Germany, the process stability of the LDF diode laser in mass production could be tested.