Characterization of reinforcement distribution inhomogeneity in metal matrix composites

The non-uniformity of reinforcement distribution in metal matrix composites (MMCs) can have significant effects on the plastic deformation and failure characteristics of these materials. Characterization of the reinforcement arrangement, in terms of a ‘random’ or ‘clustered’ distribution, is thus important. In the present work, microstructures involving ‘hard-core’, ‘single cluster’ and ‘triple cluster’ reinforcement arrangements were generated on a computer, and were characterized using a new approach to develop local reinforcement area-fraction contour maps. The construction of the contour maps followed a Voronoi tessellation-based algorithm. The entire microstructure was discretized into a number of elements, and the elemental area-fractions were determined from the ratio of the reinforcement area to the area of the enclosing Voronoi cell. The contour maps were able to distinguish between the different distributions, and capture the position, size, shape and the reinforcement area-fraction in the clusters. The cluster characteristics obtained from the area-fraction contour maps may be useful in modeling the MMC failure mechanism, which is often dominated by damage evolution in the reinforcement clusters.