On the analytical modelling of elastic properties for some particle - Reinforced aluminum matrix composites

A study was made to evaluate the applicability of seveal micromechanics mod els that predict the variation Of the elastic modulus as a function of rein forcement nature and volume fraction for some particulate-reinforced metal matrix composites. The composites were made by Vortex casting and based on a commercial alumin um alloy, with either single-phase: or two-phase (hybrid) reinforcement. Th e reinforcing particles were graphite and silicon carbide, in volume fracti on concentrations of up to 10%. The three evaluated models were: the Paul model for cube-shaped inclusions, the Paul estimation of modulus upper and lower bounds and the Halpin-Tsai model. Some generalized expressions are proposed in this paper for the firs t acid the third of the cited models in order to be applied to hybrid parti culate-reinforced composites. The predictive results were overall compared with the corresponding experimentally determined composite moduli. The predictive moduli are generally situated above the experimental data, b ut the precision of the evaluation increases for the composites with prevai ling ceramic particle reinforcement. One can say that the three models are all acceptable for hybrid particulate-reinforced metal matrix composites. H owever, the expression corresponding to the Paul model seems to exceed some fitting parameters, in order to increase the accuracy of the resulting mod uli predictions.