Estimation of the effective properties of particle-reinforced metal-matrix composites from microtomographic reconstructions

A new approach for the estimation of the effective properties of real particle-reinforced metal-matrix composites is presented. The methodology relies on statistical functions of the three-dimensional structure of the composites, as obtained from micro tomographic investigations, and uses an ergodic principle for the calculation of the overall properties. Based on the symmetrical functional form of the local volume fraction and results of finite element calculations we develop the so-called mean window technique, which leads to the remarkable result that the effective linear or nonlinear mechanical properties of a composite can be obtained by averaging randomly selected windows from the real structure. Such windows should have a size at least equal to the correlation length of the microstructure and the volume fraction of the particles equal to the mean value of the distribution of the local volume fraction. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.