Thermal conductivity of Aluminum/Graphene metal-matrix composites: From the thermal boundary conductance to thermal regulation

Aluminum is a commonly used heat dissipation material, and further improvement of its cooling performance is usually by adding an appropriate reinforcement phase into its composites. Graphene holds great promise for thermal enhancement in composites due to its outstanding thermal properties. However, the systematic study of the thermal conductance of the Aluminum/Graphene (Al/Gr) interface and thermal conductivity of Al/Gr metal-matrix composites (MMCs) are still lacking. The thermal properties of Al/Gr MMCs are explored using molecular dynamics simulation methods. Thermal boundary conductance of the Al/Gr interface plays a crucial role in the whole thermal properties of the Al/Gr composite. The parameters of model size, layer number, temperature, and strain are considered. The results show that the thermal boundary conductance (TBC) decreases with increasing layer number, and reaches a plateau at n = 5. TBC falls under tensile strain and, in turn, it grows with compressive strain. The variation of TBC is explained qualitatively by the phonon coupling factor and surface potential energy barrier. The thermal conductivity of Al/Gr MMCs is computed taking into account TBC effects at Al/Gr interfaces, and its thermal conductivity increases with graphene volume content. Our findings also provide insights into ways to optimize future thermal management based on MMCs materials.