Fabrication of nanotwinned copper-graphene nanocomposites by pulse co-electrodeposition

Incorporating graphene (Gr) into nanotwinned Cu (ntCu) is expected to produce ntCu-Gr nanocomposites with enhanced structural-functional properties by taking advantage of the unique properties of ntCu and Gr. Achieving effective dispersion and robust interfacial bonding between Gr and the ntCu matrix is critical to this process. In this study, Cu-Gr nanocomposites were prepared by using pulse co-electrodeposition (PCED). An optimized microstructure comprising a high density of nanotwins and homogeneously dispersed graphene was obtained at a graphene concentration ( C Gr ) of 0.1 g/L and a pulse current density of 300 mA/cm 2 . The Gr layers were incorporated preferably in the incoherent twin boundaries (ITBs), exhibiting an orientation relationship described as (10 1 ‾ 0) Gr //(11 1 ‾ ) Cu with the matrix. The Young's modulus of the Cu-Gr samples increases with increasing C Gr , with a maximum of ∼143 GPa for C Gr of 0.3 g/L, owing to the integration of graphene. The ntCu-Gr sample with C Gr of 0.1 g/L exhibits the highest hardness of ∼2.73 GPa, resulting from the synergistic strengthening effects of the nanotwins and graphene. Our study offers a pathway for the fabrication of ntCu-Gr nanocomposites with enhanced hardness by PCED and highlights the unique interfacial structure between nanotwins and graphene.