Co-casting of Al and Al-foam

In these years, the metal foam technology has been developed for a huge trend, therefore it is believed that the metal foam material will be next tremendous need in the market. Thanks to their peculiar properties (e.g. lightweight, energy absorbing ability) metal foams can be of interest in the realization of cars component and their use in substitution of hollow parts can be hypothesized to produce innovative functional metallic parts. In this thesis, the Al foam and their use are focused in the casting process, as permanent functional cores. The topic is poorly explored in the scientific literature and in technological applications but can have important advantages such as weight reduction in comparison to dense components, the possibility to obtain «cavities» in casting objects, as well as impact energy, vibration absorption and acoustic insulation. At first 3 different aluminum foams have been considered and characterized in the present thesis. They differ for density, pore shape and dimension. These foams have then been used as cores in casting experiments. Foams and co-casted samples have been characterized by means of density measurement, optical microscopy (microstructure, pore, skin and walls dimensions, interfaces), Field Emission Scanning Electron Microscopy Equipped with Energy Dispersive Spectroscopy (FESEM-EDS) in order to investigate morphology and chemical composition, micro-hardness and compression tests to evaluate mechanical properties. Finally a second set of foams with a more homogenous dense skin and different ceramic coatings have been characterized as possible improved cores for the future casting experiments.