Cell wall mechanical properties of closed-cell Al foam

The mechanical properties of the cell wall, such as the elastic modulus, 0.2% offset yield stress and power-law hardening exponent of the closed-cell Al foam are determined using both experimental measurements and finite element analyses. A 6 × 6 × 12 cm3 ingot of the cell wall base material, which is sampled from melted Al-1.5 wt.%Ca alloy before foaming, is prepared, and its mechanical properties are initially measured to set the limit values of the mechanical properties of the Al cell wall. Two 5 × 5 × 5 mm3 Al foam specimens of completely different structures are fabricated, and directly modeled for the finite element analysis by using a microfocus X-ray CT system, 3D reconstruction program, 3D scanned data processing software, and commercial mesh generation program. Subsequently, uniaxial compression tests are carried out on the specimens, and the numerical simulations of these tests are performed using the finite element models. For the simulations, various mechanical properties for the cell wall selected from the measured properties of the base material are used. Then, the Al cell wall mechanical properties are precisely determined by comparing the computed force–displacement curves with the measured ones. Finally, the effects of each mechanical property on the compressive behavior of the foam material are analyzed.