Cu Atoms-assisted rapid fabrication of graphene/Al composites with tailored strain-delocalization effect by spark plasma sintering

Al matrix composites with the strain-delocalization effect were fabricated by spark plasma sintering using graphene nanosheets decorated with Cu nanoparticles (Cu NPs@GNS) as reinforcement. The Joule heat, thermal stress-induced dynamic crystallization and the abnormal grain growth facilitate shorter diffusion paths of Cu atoms in the Al matrix thus generating a supersaturated solid solution near the GNS/Al interface. Thereby, the intragranular plate-like θ′-Al2Cu was generated in the adjacent grains of GNS so that the strain-delocalization effect was realized. The combination of excellent strain hardening ability, transgranular fracture mode and elongated crack path results in strength-ductility synergy.