Improvement of laser beam welding by electromagnetic forces in the weld pool

Abstract

A new method to shape the geometry and to enhance the quality of weld seams is presented in this paper. Hereby, electromagnetic volume forces are produced by utilizing various origins of the magnetic field and the electric current. Acting in the liquid metal they directly affect the flow field and lead to favorable conditions for the melt dynamics and energy coupling. Experimentally conducted full and partial penetration welds in aluminum alloys with CO2 and Nd:YAG lasers demonstrate that this method can be used to influence the seam geometry and top-bead topography, as well as the penetration depth and the evolution of process pores. In the case of full penetration, it is also possible to lift the weld pool against gravitational force.