Articles techniques et présentations

The article deals with the magnetically-supported high-power full-penetration laser beam welding of aluminum. A stationary simulation was conducted accounting for the effects of natural convection, Marangoni convection and solid-liquid phase transition as well as an electromagnetic volume source term. An ac magnet below the weld specimen induces eddy currents. Consequently, Lorentz forces occur in the weld pool and prevent the melt from gravity drop-out.

It was shown, that the magnetic pressure that is resulting from the applied ac magnetic field and its eddy currents is able to compensate for the hydrostatic pressure of the liquid aluminum above. Moreover, the influence of the Marangoni stresses at the surfaces of the specimen is lowered by a magnetically induced drag component (Hartmann effect).