Mechanical behavior of aluminum alloy foams

The existing theoretical models for describing the mechanical behavior of metal foams are based on the assumption of uniform thickness of cell edges. Analysis results indicate that the mechanical behavior of closed-cell metal foams depends on their relative density, the volume fraction of solid contained in cell edges and the mechanical properties of solid cell edges. A series of mechanical testing on closed-cell aluminum alloy foams with various relative densities were conducted to measure their elastic modulus, plastic collapse strength, fracture toughness and fatigue life. Experimental results are compared to the theoretical expressions; the agreement is good. It is also verified that the existing theoretical expressions are applicable to predict the mechanical properties of aluminum alloy foams. At the same time, the cell morphology of closed-cell aluminum alloy foams is characterized and the corresponding microstructure coefficients included in the theoretical expressions for describing their mechanical properties are determined.