Simulation of process dynamics in laser beam brazing

Abstract

A transient three-dimensional simulation model of laser beam brazing was developed in order to gain a deeper understanding of the laser beam brazing process. In the multi-physical model, beam-matter interaction, heat transfer as well as melting and resolidification of base and filler material are taken into account. Furthermore, the flow dynamics in the melt and the surrounding medium is calculated. By using an appropriate wetting model, the wetting of the base material by the filler material can be simulated. Additionally, for a realistic modeling of the brazing process the movement of the filler wire is also included in the model. To verify the model, the joint cross section obtained in the simulation is compared with experimental results. The agreement between experiment and simulation confirms the capabilities of the multi-physical approach. Based on the simulation model, wetting behavior as well as melt dynamics in laser beam brazing can be analyzed. Simulations were performed that show the formation of brazing errors. These results demonstrate that detailed simulations of the laser brazing process not only provide insight into process dynamics but are also a versatile tool for process optimization and process planning.