Mechanical and microstructural characterization of aluminium foams and AFS panels for naval applications

In the paper the structural performance of aluminium foams and AF sandwich panels have been investigated. Several foam topologies (closed cell, open cell), made by means of different process routes (melt gas injection, powder metallurgy, investment casting) and with different density (from 0,2 to 0,7 g/cm3) have been analysed. Morphometric measurements have been conducted by means of SEM (Scanning Electron Microscope) and CT (Computed Tomography) analysis and subsequent digital image processing in order to assess average cell diameter and cell distributions on different section planes. Experimental tests (compression, bending, buckling, shear) have been performed to evaluate the mechanical properties of aluminium foams and their potential application for lightweight structures. The main goal of these tests is to point out the correlation between the mechanical behaviour and the physical and geometrical properties of the foam. AFS panels made of two aluminium face sheets and a foam core hold particular promise for market penetration in naval applications in which high stiffness, high damping and low weight are required. As a case study, a comparison between a traditional stringer stiffened ship bulkhead and an innovative foam sandwich panel is presented.