Laser foaming for joining aluminum foam cores inside a hollow profile

This paper investigates the feasibility of the joining process of two aluminum foam cores contained in a tubular profile exploiting laser foaming of a solid precursor. The aim is to examine the foaming process by means of external laser irradiation of a hollow steel profile, which contains two separated aluminum foam cores intermingled by a foamable solid aluminum precursor. The experimental activity showed that three process parameters should be taken into account in order to obtain a sound foam: interaction time, laser beam power density and total amount of beam energy delivered to the work-piece. A numerical simulation allowed the qualitative evaluation of the temperature field inside the solid precursor with the purpose of better understanding the effect of the chosen parameters on the process itself.