Fabrication and thermal conductivity of copper coated graphite film/aluminum composites for effective thermal management

Graphite/Al composites are promising thermal management materials due to their excellent thermal properties. However, the poor wettability between graphite and Al leads to easy formation of interfacial defects and pores, which impede the improvement of thermal properties. Cu coating was uniformly coated on the graphite films by a physical vapor deposition process to promote interfacial wetting. A novel Graphite film/Cu/Al composite material with good interfacial bonding was fabricated by an optimized vacuum hot pressing process. The results show that Cu coating is effective to improve the interfacial thermal conductance, in-plane and out-of-plane thermal conductivity of 17.4–53.2 vol% graphite film reinforced Al composites by more than 20 times, 3–4.5% and 14–25%, respectively. Graphite film/Cu/Al composites with graphite volume fraction of 17.4–53.2% have excellent in-plane thermal conductivities of 397–805 W/mK, which approach the theoretical values calculated by the thermal conductivity model of laminate composites and make them promising thermal management materials.