Thermally conductive bidirectional carbon structure enhanced heat-dissipative aluminum framework composites

Lightweight, highly integrated and miniaturized modern high-power electronic devices put forward higher requirements on the heat removal efficiency of heat sinks. Herein, the bidirectional carbon hierarchical structure consisting of high crystalline carbon (HCC) layer and carbon nanotubes (CNTs) reinforced aluminum foam (AF) composites were prepared by the combination process of dopamine annealing and plasma enhanced in-situ growth. The hybrid carbon reinforcements establish two high-speed thermal conduction paths on the surface of the aluminum skeleton, enhancing the skeleton axial transport efficiency. The calculation results of non-equilibrium molecular dynamics (NEMD) reveal that the utilization of an optimal thickness of HCC layers can effectively strengthen the axial thermal conduction flux of the skeletons while minimizing the detrimental impact on radial heat flow from aluminum substrate to CNTs caused by thermal resistance. The composites exhibit the effective thermal conductivity of 43.17 W·m -1 ·K -1 , which is 5.6 times higher than that of the pristine AF. The instantaneous cooling rate of 16.1 K·s -1 and the cooling efficiency of 34.6% demonstrate the superior heat dissipation performance of the composites compared to other similar carbon phase reinforcing heat sinks. Therefore, the composites prepared in this work holds promising potential for heat removal applications.