Correlation Modeling between Morphology and Compression Behavior of Closed-Cell Al Foams Based on X-ray Computed Tomography Observations

Abstract

In the last decades, great attention has been focused on the characterization of cellular foams, because of their morphological peculiarities that allow for obtaining effective combinations of structural properties. A predictive analytical model for the compressive behavior of closed-cell Al foams, based on the correlation between the morphology of the cellular structure and its mechanical response, was developed. The cells’ morphology of cylindrical specimens was investigated at different steps of compression by X-ray computed tomography, in order to detect the collapse evolution. The structure, typically inhomogeneous at local level, was represented by developing a global virtual model consisting of homogeneous cells ordered in space, that was fitted on the experimentally detected structure at each deformation step. As a result, the main parameters characterizing the two-dimensional cells morphology (equivalent diameter, circularity), processed by the model, allowed to simulate the whole compression stress–strain curve by enveloping those obtained for each step. The model, fitted on the previous foam, was validated by comparing the simulated stress–strain curve and the corresponding experimental one, detected for similar foams obtained by different powder compositions. The effectiveness in terms of an accurate prediction of the compression response up to the final densification regime has been confirmed.

X‐ray Tomography and Tomoscopy on Metals: A Review

“…[ 203 ] In a further study, a short‐range order of monodispersed cells in foams produced by the melt route with a special gas injector was discovered and described. [ 204 ] Girolamo et al investigated the correlation between morphology and compression behaviour [ 205 ] and Neu et al for the specific case of aluminum foam sandwich panels. [ 206 ] X‐ray tomography was also used as an input for thermal [ 207 ] or electrical [ 208 ] conductivity analyses in metal foams as well as for finite‐element simulations.…”

Parametric Control via the Algebraic Expression of Lotus-Type Pore Shapes in Metals

“…Porous materials such as lotus-type porous metals feature good direction-dependent mechanical properties, such as tensile, compression, bending, and fatigue strength, and physical and thermal properties, such as sound absorption and thermal and electrical conductivity [ 1 , 2 , 3 , 4 , 5 , 6 ]. These properties act better in parallel than perpendicularly [ 1 ].…”

The Influence of Foaming Agents on Aluminium Foam Cell Morphology

“…By applying the DVC method, the internal structure behavioral data are also obtained, since CT scanning of the sample is performed during the entire loading process. By applying such a method during compression or tensile testing, it is possible to gain an insight into the deterioration of the internal cell walls of the porous sample [48][49][50][51].…”