Laser beam welding of light alloys has always represented a big challenge for both
designers and technologists due to the large number of process parameters to take into account and
the variable responses of the different materials to be welded. In this paper the results of
experimental research on laser beam welds of innovative heat treatable aluminum alloys is reported.
The well known T geometry (a stringer welded to a skin) has been considered. Two different skins
have been analyzed: AA 2139 and AA 6156, both in form of rolled sheets. Two different stringer
have been analyzed: AA 2139 and PA 765, both in form of extruded parts. AA 4047 has been used
as filler wire. In the first part of the paper, all the steps leading to the realization of sound welds will
be described. The criteria used in order to assess the soundness of a weld was the absence of
defects, such as cracks or large pores, verified by means of NDE. In the second part of study, both
micro structural analysis and mechanical characterization of welds will be described and discussed.
Conclusions will demonstrate the importance of the influence of chemical composition of the parts,
above all stringer. The performance of the best welds, however, were very close to those of parent
materials.
Benefits of very high feed rates for laser beam welding of AlMgSi aluminum alloys