Achieving High Strength in Cu/Graphene Composite Produced by High Pressure Torsion

Cu/graphene metal matrix composite is promising for a wide range of applications. However, the important problems in the synthesis of the Cu/graphene composite exist, associated with the poor dispersion of the graphene in the matrix and weak interfacial bonding. High pressure torsion processing supplies a possibility to obtain bulk samples with a nanocrystalline structure, without pores and contamination from dissimilar materials. This processing was successfully used for fabrication of the Cu/graphene composite out of thin copper foils coated with a monolayer of graphene. Microstructural characterization of the processed disks demonstrated microstructure with an equiaxed grain size of about 300 nm. The process significantly increased microhardness of Cu/graphene composite. The tensile tests showed the value of the tensile strength reached 670 MPa at room temperature.