In situ synthesis of high content graphene nanoplatelets reinforced Cu matrix composites with enhanced thermal conductivity and tensile strength

The difficulty of dispersing high content of graphene nanoplatelets (GNPs) in the metal matrix limits the strengthening efficiency of GNPs reinforcement. Herein, high content GNPs were synthesized on the surface of Cu powders using chemical vapor deposition with solid carbon source incorporating impregnation-reduction route, which made GNPs uniformly dispersed and improved the interfacial bonding between GNPs and Cu matrix. Then, the composites were densified by vacuum hot pressed sintering followed by multi-step hot rolling process, during which the orientation distribution of GNPs was achieved. After a rolling reduction of 70%, the composite materials containing 12 vol% GNPs were increased by 44% in yield strength (256 MPa) compared with that of pure Cu (178 MPa). Furthermore, the in-plane thermal conductivity was increased by 17% (441 W/mK) when the GNPs content is 15 vol%. This work sheds light on designing structural and functional integrated Cu matrix composites. (C) 2019 Elsevier B.V. All rights reserved.