Metallic vapor ejection effect on melt pool dynamics in deep penetration laser welding

The hydrodynamics phenomena involved during the laser welding process are very complex. Among the possible involved mechanisms controlling the hydrodynamics of the weld pool, it is well known that the melt displacement resulting of the local pressure applied to the liquid surface as a result of the evaporation process, plays an important role. We would like to show in this article that, using specific experiments based on twin or triple spot interaction geometry, the friction forces of the metal vapor escaping from the keyhole are also shown to have a very important role for the hydrodynamics of the melt pool along and around the keyhole.