A review of models for effective thermal conductivity of composite materials

The solutions of Maxwell and Rayleigh were the first of many attempts to determine the effective thermal conductivity of heterogeneous material. Early models assumed that no thermal resistance exists between the phases in heterogeneous material. Later studies on solid-liquid and solid-solid boundaries revealed that a temperature drop occurs when heat flows through a boundary between two phases and, as a consequence, the interfacial thermal resistance should be included in the heat transfer model. This paper is a review of the most popular expressions for predicting the effective thermal conductivity of composite materials using the properties and volume fractions of constituent phases. Subject to review were empirical, analytical and numerical models, among others.