What thermal conductivity anisotropy exists in composite materials?

Thermal conductivity anisotropy in composite materials refers to the directional dependence of heat transfer properties, where heat flows more efficiently in one direction than others. This phenomenon arises due to the heterogeneous nature of composites, which combine two or more distinct materials (e.g., fibers and matrices) with differing thermal conductivities. For instance, carbon fiber-reinforced polymers exhibit higher thermal conductivity along the fiber direction compared to perpendicular directions.

The degree of anisotropy depends on factors like filler alignment, interfacial thermal resistance, and volume fraction of conductive phases. Applications leveraging this property include aerospace components, electronic packaging, and thermal management systems, where controlled heat dissipation is critical. Understanding and optimizing thermal conductivity anisotropy enables tailored material design for enhanced performance in specific environments.