Modification of the weld penetration characteristics in laser deep welding by the use of instationary gas flows

Abstract

The present report focuses on the integration of a technology for generating temporally alternating (pulsed) gas flows in the field of laser welding. The technical realization required the specific adaptation of the three core elements of the gas pulse system (valve, section of measurements, control system) to realize new parameters for laser welding. These parameters allow for a positive influence on the joining process and on the results of welding, respectively. By means of temporal control of the gas volume flow in combination with the laser welding process, it was possible to produce a force effect on the molten pool and subsequently to improve the characteristics of laser-welded seams. The effects occurring through the use of an instationary gas flow were evaluated by using the "classically" metallography and through the use of digital image processing. In parallel, the effect of a pulsating gas flow on the melting zone was simulated by using specific software in order to be able to make further statements about the effects.