Comparative study on carbon nanotube and graphene reinforced Cu matrix nanocomposites for thermal management applications

摘要

Cu-1 wt% carbon nanotube (CNT) and Cu-1 wt% multilayer graphene (Gr) nanocomposites were produced by 5 h mechanical milling. Then consolidations through three different techniques of cold press, hot press and spark plasma sintering (SPS) were done. Structure, microstructure, relative density, mechanical properties, electrical and thermal conductivity, thermal stability and coefficient of thermal expansion (CTE) were evaluated. Relatively good dispersion of CNTs and Gr in the Cu matrix were obtained. A decrease in particle size was much more notable in CuGr powder. The crystallite size decreases to 36 and 20 nm with the addition of both CNT and Gr, respectively. A comparison of the consolidation technique of SPS with others showed the maximum relative density, hardness and yield strength obtained by the SPS method. The relative density of CuGr and CuCNT nanocomposites consolidated by SPS was found to be 95-97%. The hardness of CuGr nanocomposite was 76 BHN, which was approximately 81 and 9% higher than of the Cu sample and CuCNT nanocomposite, respectively. The higher yield strength of 210 MPA was obtained for CuGr nanocomposite consolidated by SPS. CNTs and Gr are thoroughly embedded in the matrix and bonded tightly. The High electrical conductivity of 78%IACS, the thermal conductivity of 351 W/mK were achieved in the CuGr nanocomposite in combination with a CTE of 12.8 ppm/K. Both thermal distortion parameter (TDP) and softening percent of the nanocomposites were decreased by the addition of Gr and CNT. The present work implies that CuGr nanocomposite may be a good candidate for thermal management applications.