Study and optimization of shielding gas nozzle used for laser welding

Gas shielding devices plays an important role in the process of laser welding. The gas flow emitted by various gas nozzles such as inclined tube or coaxial nozzle has been studied. Their ability for assuring a correct protection against oxygen or nitrogen contamination of the interaction zone has been studied both experimentally, using a mass spectrometer, and numerically by using hydrodynamics simulations. Several geometrical configurations were used. Preliminary experimental results on the consequences for the weld quality are presented.