Microstructure and thermal conductivity of graphite flake/Cu composites with a TiC or Cu coating on graphite flakes

Graphite flake/Cu composites with Cu or TiC coatings on the graphite surface were fabricated via a powder metallurgy method. The effect of the flake's surface coating on the microstructure and thermal conductivities of the graphite flake/Cu composites was studied. The results show that a good contact interfacial structure is established when the TiC or Cu coating is introduced. The thermal conductivity of the TiC- and Cu-coated composites with a 60 vol% flake reached 668 W m(-1) K-1 and 612 W m(-1) K-1, respectively. A modified Diffuse Mismatch Model for anisotropic graphite was established to estimate the interfacial thermal resistance, and the Effective Medium Approach was used to analyze the thermal conductivity behavior of composites. The results show that both coated composites exhibit low interfacial thermal resistance, resulting in high thermal conductivity in the X-Y plane. The thermal conductivity may be further enhanced if a preferable alignment control is used.