Enhanced Thermal Conductivity and Tensile Strength of Copper Matrix Composite with Few-Layer Graphene Nanoplates

Microstructure, thermal conductivity and tensile properties of copper foils are significantly affected by few-layer graphene nanoplates (FLGNPs) as reinforcement embedded into Cu matrix. In the present study, FLGNPs and Cu²⁺ were co-deposited on the Ti substrate by direct current (DC) electrodeposition to obtain flexible Cu-FLGNPs composites. The texture orientation, phase structure, surface morphology, interface between FLGNPs and Cu matrix of the Cu-FLGNPs composites were characterized. The results show that thermal conductivity and tensile properties of the Cu-FLGNPs composites were increased firstly and then decreased in the process of electrodeposition. Thermal conductivity of the Cu-FLGNPs composites was enhanced from 311 ± 9 W m⁻¹ K⁻¹ characteristic for Cu up to 444 ± 13 W m⁻¹ K⁻¹ when the Gr content was 0.8 g L⁻¹ and the graphene defect density was 6.30×10¹⁰ cm⁻². Tensile strength of the Cu-0.8FLGNPs composites was 397 MPa, which was improved by 34% compared to the Cu matrix counterparts. Furthermore, the modified thermal model was proposed to evaluate the difference between experimental and theoretical thermal conductivity. The thermal conductivity mechanism was mainly ascribed to graphene defects, electron scattering, phonon scattering and interfacial thermal resistance. The electrodeposition of the Cu-FLGNPs composites provides a feasible route for heat dissipation of electronic and thermal management devices.