▎ 摘　　要

Exploring the influence of reinforcement modification on the localized mechanical instability of composites with heterogeneous grain structure is of great importance for tailoring the comprehensive performance. This work realizes the multi-scale structure adjustment of graphene nanoplatelets reinforced Cu matrix composites by in -situ synthesis and ball mill mixing. It was elucidated that graphene nanoplatelets encapsulated Al2O3 with podlike convex structure enhance the interfacial cohesion and the interaction between reinforcement and matrix with heterogeneous grain, which exerts prominent contribution to the elimination of strength-ductility trade-off. Meanwhile, the composites have good electrical conductivity (96.5 IACS%) due to the strict control of interfacial electron scattering by the encapsulated structure. This novel multiscale structural regulation route shows the capacity of developing composites with the exceptional comprehensive performance towards prospective applications.