▎ 摘　　要

In graphene nanoplatelets (GNPs) reinforced 2024 Al alloy (2024 Al-GNPs) composites, both GNPs and precipitates play important roles in enhancing mechanical properties. To obtain the synergistic strengthening effect of GNPs and precipitates, it is necessary to study the influence of GNPs on the precipitation in 2024 Al-GNPs composites. In this study, 2024 Al-GNPs composites were prepared by spark plasma sintering, and the microstructure and mechanical properties were studied. Homogeneous distributed GNPs promote the precipitation of Al2Cu by providing heterogeneous nucleation interfaces and introducing dislocations. Based on the refinement of Al2Cu in composites, the phase-field model was established to demonstrate that GNPs suppress the segregation of Cu atoms at grain boundaries. In addition, the dislocations introduced by GNPs were found to affect the precipitation sites of Al2Cu, and the evolution was simulated by the phase-field method. This work provides new insight to further enhance the mechanical properties of Al-GNPs alloy composites.