Microstructure and mechanical properties of Cu\Ni-coated α-Al2O3w and graphene nano-platelets co-reinforced copper matrix composites

graphene nano-platelets (GNPs) and alpha-Al2O3w reinforced laminated Cu matrix composites were successfully prepared by flake powders metallurgy (FPM) and vacuum hot pressing sintering. In order to compare the effects of different coatings on the interfacial and mechanical properties, Cu\Ni-coated were used for surface modification of reinforcement surface. The microstructure, interfacial bonding and mechanical properties of Cu\Nicoated GNPs and alpha-Al2O3w co-enhanced laminated Cu matrix composites were investigated. The results showed that composites with Cu coating on the surface of reinforcement had poor contact and lower mechanical properties. In contrast, the introduction of Ni coating improved interfacial bonding and also brought about solid solution strengthening of matrix. When the content of Ni coating GNPs was 1 wt%, tensile strength reached 336.12 MPa and elongation was 16.36 %. On the one hand, the Ni coating promoted interfacial bonding, and good interface brings better load transfer and interfacial strength. Meanwhile, alpha-Al2O3w and GNPs with different aspect ratios showed better strengthening effects through various strengthening modes such as drawing and fracture. On the other hand, the laminated structure allowed crack extension to be transferred to other planes, the crack deflection process consumes more energy, and composite achieves a balance of strength and toughness. This work provides a new idea to improve interfacial bonding of composites and obtain high strength and toughness.