In-situ growing carbon nanotubes reinforced highly heat dissipative three-dimensional aluminum framework composites

Abstract

The demand for lightweight heat dissipation design in highly miniaturized and portable electronic devices with high thermal density is becoming increasingly urgent. Herein, highly thermal conductive carbon nanotubes (CNTs) reinforced aluminum foam composites were prepared by catalyst chemical bath and subsequent in-situ growth approach. The dense CNTs show the intertwined structure features and construct high-speed channels near the surface of the skeletons for efficient thermal conduction, promoting the transport efficiency of heat flow. The regulation of the process leads to a proportion increase in the (1 1 0) crystal plane of the aluminum substrate. The calculation results of non-equilibrium molecular dynamics (NEMD) demonstrate that (1 1 0) crystal plane is conducive to enhancing thermal boundary conductance thus the desirable equivalent thermal conductivity is obtained in the model system. Moreover, the phonon behaviors at the heterointerface observed in phonon density of states spectrums (PDOS) show that the interface system with (1 1 0) crystal plane possesses the superior coupling effect suggesting the brilliant transmission capacity. The theoretical results of NEMD and PDOS provide a microscopic explanation for the high thermal conductivity observed in the prepared composites with a high content of Al (1 1 0) crystal plane. The composites exhibit a thermal conductivity of 30.63 W·m^-1·K^-1, improved by ∼300 % as compared to unmodified aluminum foam. The cooling efficiency of 28.63 % obtained in the composites indicates outstanding heat dissipative performance among other similar works. The composites prepared in the work could hold bright prospects for the thermal management field.

Keywords: Aluminum foam; Carbon nanotubes; Heat transport; In situ; Thermal conductivity.