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A Lattice Monte Carlo (LMC) method was employed to predict the effective thermal conductivity (ETC) of closed-cell aluminum foams with porosities between 0.828 and 0.894 through a cubic unit model. The numerical results demonstrated a linear dependency on the relative density when the cell wall thermal conductivity (CWTC) was set as that of pure aluminum; the dependency had large deviations from the measured ETCs obtained via a steady-state comparative method. To characterize the actual CWTC, its relationship with the ETC was deduced, and its value was determined through the measured ETC. On the other hand, the cubic unit model was improved with consideration of the plateau borders characterized through Image-Pro software. With the corrected CWTC and the improved cubic unit model, the numerical results agreed well with the measured results. Hence, the LMC method can be used to predict the ETC of closed-cell aluminum foams accurately through a cubic unit model, provided that the relative density, the CWTC and the plateau borders are taken into account.

The effective conductivity of binary composites may be estimated through a number of analytical, empirical and numerical methods. These methods must incorporate the relative conductivities, the volume fractions and morphologies of the constituent materials. The concept of microstructural efficiency is introduced in this paper as a means of quantifying the effect of morphology on effective conductivity in a composite. The variation of microstructural efficiency on structured prismatic and three dimensional morphologies is calculated using a Lattice Monte Carlo method. This information enables discussion of the advantages and disadvantages of particular morphologies as conductors or insulators in addition to providing a method for calculating effective conductivity.

Advanced pore morphology (APM) foam elements have a spherical outer skin and a porous inner structure. In this study, the method of Lattice Monte Carlo is applied to determining the thermal characterisation of periodic structures formed by spherical APM foam elements. Two diameters, i.e. 5 mm and 10 mm spheres, are considered. To this end, micro-computed tomography data of real samples is converted into numerical calculation models. This procedure allows the accurate geometric representation of the complex internal foam geometry. Lattice Monte Carlo is then used to obtain the effective thermal conductivity of partial and syntactic structures made up of APM foam elements. Samples are analysed for variation in absolute and directional (anisotropy) thermal conductivity.