Interfacial Design of Graphene Nanoplate Reinforced Copper Matrix Composites for High Mechanical Performance

Considered to be an excellent reinforcement, graphene has been widely studied to enhance the mechanical properties of copper (Cu) matrix composites. However, the poor interfacial bonding between graphene and the Cu matrix is a tricky problem for achieving high strength and good ductility. In this paper, with the construction of a titanium (Ti)-rich transition layer, the improved interface between graphene nanoplates (GNPs) and the Cu matrix is achieved through a powder-metallurgy-based strategy including vibration mixing and spark plasma sintering (SPS). The obtained GNP-Ti/Cu composites demonstrate a yield strength of 295.6 MPa and ultimate tensile strength of 415.8 MPa, which are 239.0% and 100.6% higher than those of pure Cu. Compared with GNP/Cu composites, the GNP-Ti/Cu composites also exhibit an increase of 115.9% and 66.7% in yield strength and ultimate tensile strength, respectively. The extremely high strength is attributed to the modified interface which results in efficient load transfer, grain refinement, and dislocation storage capability. This work provides a feasible method for manufacturing nanocarbon reinforced Cu matrix composites with high mechanical performance through interfacial design.