Simulation and quantitative assessment of finite­size particle distributions in metal matrix composites

A series of finite­size particle distributions were simulated to investigate the effects of particle size, shape, orientation, and area fraction on the quantification of homogeneity in structural particulate metal matrix composites (MMCs). It is found that, for nominally random distributions, the values of conventional centre-to-centre nearest-neighbour spacing parameters are influenced by particle morphology, and, as such, are unsuitable for characterising distributions of finite-size particles. However, the coefficient of variation of the mean near-neighbour distance COV(d mean ), derived from particle interfaces using finite-body tessellation, appears independent of particle shape, size distribution, orientation, and area fraction, while showing great sensitivity to particle clustering. In the range of particle morphological characteristics studied, the random distributions were found to exhibit a consistent value of COV(d mean ) equal to 0.36±0.02. The degree of inhomogeneity of any given distribution may then be evaluated by simply comparing the measured COV(d mean ) with this value.