Laser welding of aluminum foam sandwich panels [Saldatura laser di pannelli sandwich in schiuma di alluminio]

The paper describes the results about the laser and laser-TIG welding of Aluminum Foam Sandwich. The panels used are produced by powder metallurgy technology and this permits to have a metallurgical bonding between skin and core. So, this material is completely metallic and has an excellent stability even in case of fire. These features allow to choose the ASF as new lightweight material for structural components also in the field of transport. One of the limitations relating to this type of materials is the maximum available size (2.5 × 1.2 m), which requires the development of special processes of junction with low heat input to reduce, as much as possible, the dimension of the area affected by the welding process. It should be considered the fact that it is possible to weld only the skins of the sandwich, so a discontinuity in the core remains intrinsic to the welding process. Therefore, it is appropriate to employ a transition element in the welding line to achieve a link between the two skins. The troubleshooting about the laser welding regards both: the common difficulties in the laser welding of the aluminum alloys of the skin and some other problems due to the presence of eutectic alloys in the core than we can't remove completely.