A comparison among FE models to simulate metallic foams forming – An experimental validation

Metallic foams are new materials mainly produced by expansion in a proper chamber and mainly characterized by internal voids: a material characterized by a very low density is obtained in this way. A lot of foamed components are commonly produced, directly by injecting a gas or foaming agent into molten metal inside a closed die. However, secondary operations on these materials can play an important role in order to enhance the foam production flexibility. From the above considerations, the deformation behaviour of an aluminium foam was investigated by compression tests. The study compares three different numerical analyses highlighting their points of strength and weakness in order to verify their applicability in process design. More in detail, two models based on the implicit formulation were investigated; in one case, the billet material was set as porous object with the material density which was calculated and updated as part of the simulation. The second implicit analysis, instead, was built using the plastic material formulation; the porosity, in this case, was physically created introducing voids within the workpiece.The latter simulation class was carried out through an explicit investigation; an efficient model construction was proposed introducing spherical surfaces connected each other with plans. Experimental data were used to validate the calculated results and a discussion concerning the three different numerical analyses was finally reported.