Modeling of interfacial design and thermal conductivity in graphite flake/Cu composites for thermal management applications

Abstract

As a promising thermal management material, graphite flake/Cu composite materials have received much attention. Interface design is critical to the thermophysical properties of graphite flake/Cu composites. This work provides an overall theoretical evaluation of the effect of various components and their carbides as interface layers on the interfacial thermal conductance and thermal conductivity of graphite flake/Cu composites for the first time, by developing the extended diffusion mismatch model and Hatta-Taya model. An example of composites with different thickness of Cr7C3 interface layer, together with the experimental results from the references, is provided to verify the rationality of the model. Based on the model, a critical thickness for each interface layer is calculated. When the thickness of interface layer was maintained at less than the critical thickness, the composite had good thermal conductivity performance. W, Mo and WC, which are thickness-insensitive and have low solubility in the Cu matrix, are the most promising candidates to improve the thermal performance of graphite flake/Cu composites. The results of this analysis provide theoretical guidance for material selection for interface design and can also be applied to other matrix composites.