Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Temperature Controlled Laser Brazing with High-Power Diode Lasers

Project Status: finished

In recent year laser brazing has become widely accepted as a reliable joining technology for visible joints in car body manufacturing. There are, however, numerous requirements with regard to system technology that have to be met in order to guarantee a fault-free application. Variations in component measurements or inaccuracies of the guiding machine during reorientations of the processing head can lead to process failures. According to state of the art in series production, it is not possible to avoid sporadic brazing defects which call for a subsequent hundred percent inspection of the components. It is therefore the goal of this research project to extend the process limitations of laser brazing by means of temperature control and thus to guarantee faultless seams. The first step is the construction of a flexible brazing head with integrated temperature measurement which is then connected to a fibre coupled high-power diode laser. Fundamental investigations are carried out to determine the temperature during the laser brazing process. Subsequently, the process parameters are systematically varied in order to deliberately produce defective brazing seams. The measurement signals thus detected are characterised with regard to significant attributes. The investigations permit systematic monitoring of the laser brazing process and detection of process failures. In a next step, a process control for laser brazing is to be designed and the results are to be transferred to more complex seam geometries.

Letztes Update: 01.01.2010