Dynamik und Stabilität der Dampfkapillare beim Laserstrahltiefschweißen

The keyhole which is typical for laser deep penetration welding is responsible for the highly dynamic process behavior, which results in unwanted pore and spatter formation. This work aims to better understand the dynamic keyhole properties and occurrence of process defects. Therefore, a semi-analytical model is developed and validated by optical emission analysis. Spatter characteristics are evaluated in high speed videos and porosity in x-ray analysis. Correlations between keyhole behavior and spatter and pore characteristics could show that pores can form due to a keyhole collapse and spatter detachment requires more than the momentum from keyhole wall fluctuations. Dynamic behavior and process defects are influenced by the spatial laser intensity distribution.