Energy efficient brazing by using the deep penetration effect

• Applicant: Professor Dr.-Ing. Frank Vollertsen
• Subject Area: Production Automation and Assembly Technology
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 326408602

Increasing process efficiency is of high interest in science and industrial applications in the field of laser material processing. In laser beam welding, techniques like deep penetration welding or spatial beam modulation strategies are commonly used while those methods have not been in the focus of research in laser beam brazing processes. In order to influence the temperature field during laser beam brazing mainly two-beam-processes and the effect of beam shaping have been investigated and developed.The aim of this work is to prove that a highly energy efficient brazing process can be realized by using the deep penetration effect. If possible, additional pre-heating of the specimen should be avoided. The main difference to conventional laser beam brazing is the local but significantly higher absorption of the laser power due to keyhole evolution in the filler material. In combination with a spatial beam modulation this effect can be used to guarantee a variable and controllable efficient heat input. Therefore, the characterization of the wetting behavior depending on the produced temperature fields in the filler and base material and the fluid dynamics as well as material properties is necessary. In order to verify the efficiency improvement the process efficiency is evaluated for the keyhole processes and is compared to conventional laser beam brazing.

• DFG Programme: Research Grants