Mechanical Properties and Deformation Behavior of Open-Cell Type Aluminum Foams with Structural Conditions and Alloy Composition

Open-cell type aluminum foams with various structural conditions and alloy compositions were manufactured using the replication casting process. The porosity of the foams ranged from 55% to 62%, with pore sizes of 0.7 similar to 1.0 mm, 1.0 similar to 2.0 mm, and 2.8 similar to 3.4 mm. The alloys employed included commercial A356 and A383, as well as Al-6Mg-(0, 2, 4, 6)Si alloys. Compression tests were conducted under various conditions of the foams, and the results were comparatively analyzed based on the detailed structural conditions and alloy compositions. It was observed that for the same alloy composition and equivalent porosity, a reduction in pore size led to an increased number of cell walls, enhancing energy dispersion and resulting in higher compressive yield strength and energy absorption. Under the same pore size, a decrease in porosity increased the relative density and cell wall thickness, leading to improved compressive yield strength and energy absorption. Furthermore, compressive evaluation based on alloy composition revealed the influence of the inherent mechanical properties of the material on the mechanical properties of open-cell type aluminum foams. Specifically, it was confirmed that alloys with higher ductility exhibited elastic behavior of the internal cells under external stress, significantly influencing the energy absorption of foams.