Realizzazione e caratterizzazione di strutture sandwich di acciaio con core in schiuma di Al

The present work describes the results carried out in the manufacture of sandwich panels with stainless steel (SS) AISI 316 skins and an aluminium alloy AlSi10 foam core. In particular, a method to realize in-situ bonding between the (SS) skins sheets and the aluminium foam core is described. The production of the sandwich was done in two steps: the first step for the manufacture of the composite precursor, by hot and cold pressing, made from two sheets of (SS) with in the middle a foamable precursor of AlSi10; during the second step, the composite precursor was been foamed in the oven at 640 °C. The interface layer between SS-precursor of the composite, before and after foaming, was been investigated by SEM observations to reveal possible defects. The interdiffusion of alloying elements across the metallurgic bonding layer were analysed by EDS, XPS and AES. The results evidenced that an interface of 40 µm was formed after foaming; the chemical gradients shown across the interface testify a good interdiffusion with consequent excellent quality of metallurgical bonding.