Fabrication and thermal conductivity of copper matrix composites reinforced with Mo2C or TiC coated graphite fibers

•A Mo2C or TiC coating was synthesized on the graphite short fibers by means of molten salt method.•Compared to the uncoated Cu matrix composites, an improvement thermal conductivity was observed in coated composites.•An original theoretical model was proposed to estimate the interfacial thermal resistance.

Graphite fiber reinforced Cu-based composites have good thermal conductivity, low coefficient of thermal expansion for heat sink applications. In these composites, the quality of interfacial bonding between the copper matrix and the graphite fibers has significant influence on the thermal properties of composites. In this study, two different carbide coatings (Mo2C or TiC) were synthesized on graphite fiber to promote the interfacial bonding in composites. Fibers/Cu composites had been produced by spark plasma sintering process. The results showed that the densification, interfacial bonding and thermal conductivity of coated composites were improved distinctly compared to that of uncoated ones. The enhanced composites present 16–44% increase of thermal conductivity in X–Y plane. An original theoretical model was proposed to estimate the interface thermal resistance. The result showed that the interfacial thermal resistance was largely reduced by one order of magnitude with the introduction of carbide interlayer.

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