PACKING DENSITY OF COMPOSITE POWDER MIXTURES

A model of particle packing in binary composite systems is developed. The effects of both inclusion surfaces and touching inclusions on the packing density are taken into account. To implement the model, a statistical approach is used to determine the number of inclusion contacts as a function of inclusion content. The statistical approach indicates that the average number of inclusion contacts is a linear function of the inclusion volume fraction, a result which agrees very well with independent computer simulations. The model suggests that the packing efficiency, defined by the ratio of the packing density to the ideal packing density (as originally derived by Furnas), is governed by the inclusion volume fraction (f(i)) and the particle to inclusion size ratio (r). Good agreement is obtained between the theory and experimental literature data.