A Numerical Study on the Thermal Conductivity of Hybrid-Filler-Nanoparticle Composite Materials

Augmenting the thermal conductivity of polymer materials is actively being attempted by adding one or more fillers with higher thermal conductivity into matrix materials. In this study, the effective thermal conductivity of composite materials was investigated numerically under the effects of the thermal conductivity ratio between two particle fillers and the matrix material, and the particle volume fractions. The results indicate that the effective thermal conductivity of composites containing hybrid filler is higher than that of single filler. The effective thermal conductivity increases with the increase of thermal conductivity ratio between two fillers in general when this ratio is less than unity, and the maximum effective thermal conductivity approaches when this ratio is less than and close to unity. However, this trend is changed when this ratio is greater than unity. Based on the results, a generalized correlation is proposed as a function of four non-dimensional parameters. The results obtained in this study can be widely utilized for predicting the thermal conductivity of hybrid-filler-nanoparticle composite materials.