Dislocation Entangled Mechanisms and 3D-2D Interface in Copper-Graphene Nanocomposite Fabricated by High-Pressure Sintering

Graphene reinforced Cu-based nanocomposite was synthesized using high-pressure (~8 GPa) sintering or HPS. The HPS at 300°C processed composites successfully achieved 96% of relative density with 84% IACS improvement in electrical conductivity. Scanning and transmission electron microscopy showed that graphene reinforced uniformly and good combination between graphene and Cu matrix. A significant increase in nanohardness (~2.4GPa) and Young’s modulus (~94GPa) was retained during straining by HPS. Molecular dynamics (MD) simulations on graphene-reinforced nanocrystalline (NC) Cu (Gr-NC Cu) has exhibited higher nanohardness and Young’s modulus than NC Cu, and the MD results are well agreed with experimental data. The structural and defects evolution of NC Cu and Gr-NC Cu specimens has been investigated under the nanoindentation process.