Micro-scale prediction of effective thermal conductivity of CNT/Al composites by finite element method

Abstract Thermal conductivity of CNT/Al composites is considered to be an important property on composites design. However, the effect of microstructure on thermal conductivity has few been reported. In this study, a 3D multi-scale finite element model was developed to predict the effective thermal conductivity of CNT/Al composites, and the influences of CNT configuration, heat transfer direction, interfacial thermal resistance and volume fraction were investigated in detail. Five configurations of CNT were constructed including randomly arranged, evenly oriented, layered, bundled and networked. The results show that the CNT configuration plays a major role for the effective thermal conductivity of CNT/Al composites. The CNT/Al composite with layered configuration has the highest thermal conductivity, and when the volume fraction of CNTs is about 3.7 %, the CNT/Al composite displays an excellent effective thermal conductivity of 400 W/m·K, which increases about 84 % than that of the Al alloy. Moreover, the interface and thermal loading direction also have obvious effect on the thermal conductivity of the composites. The calculated results are in good agreement with experimental data existing in literature. The obtained findings in this study could provide a good theoretical basis for designing high thermal conductivity CNT/Al composites.