Quantifying the dispersion of mixture microstructures.

A general method to quantify the inclusion dispersion of mixture microstructures has been developed. The dispersion quantity, D, is defined as the probability of inclusion particle free-path spacing falling into a certain range of the mean spacing mu, according to the particle spacing data frequency distribution. Two quantities, D(0.1) and D(0.2), are proposed, which are the probabilities of the particle free-path spacing falling into the ranges of mu+/- 0.1 mu and mu+/- 0.2 mu, respectively. Both normal and lognormal distributions are discussed, and in both cases, the quantities D(0.1) and D(0.2) are specified as monotonous increasing functions of mu/sigma, where mu and sigma; are the mean particle free-path spacing and standard deviation, respectively. Examples of composite are presented to quantify the dispersion of foreign reinforcements based on the proposed method.