A simulation method to evaluate electrical conductivity of closed-cell aluminum foam

Aluminum foam is a functional material which is highly porous with cells of stochastic geometry. In distinction to polymer foam, aluminum foam is electrically conductive and has typical applications in many engineering areas. Optimal design and manufacture of foam structure usually require detailed understanding of the electrical property of the aluminum foam. In this study, a three-dimensional finite element numerical model based on the statistic characteristics of the geometrical structure of the closed-cell aluminum foam was proposed. The proposed numerical method was applied to study the property of the current conduction and to clarify the dependence of the electrical conductivity on the porosity as well as the cell size. A shape factor defined based on the numerical simulation results is introduced to the theoretical model of the electrical conductivity regarding porosity, which can describe the relationship between the electrical conductivity and the porosity of the closed-cell aluminum foam properly. It was found that the porosity has a negative effect on the electrical conductivity in a power law approximately, while the cell size has a slight effect on the electrical conductivity of the closed-cell aluminum foam. Finally, the simulation results were compared to the experimental ones and their good agreement demonstrated the feasibility and accuracy of the proposed numerical model of the closed-cell metallic foam.