Effect of graphene lateral size on the microstructure and properties of graphene/copper composites.

Copper matrix composites reinforced with graphene nanoplatelets (GNPs) were prepared by vacuum hot pressing of ball milled mixtures of powders. Two grades of GNPs were used; one with average thickness of 2 nm and average lateral size of 6  μ m and another with much larger lateral size of 80  μ m. Microstructure and properties of as-prepared composites containing 10 vol.% GNPs were studied. The GNPs sheets are uniformly distributed and well aligned in the Cu matrix. The microstructure observation shows that the GNPs-2–6 exhibits a better dispersion in the Cu matrix than GNPs-2–80. The addition of fine GNPs-2–6 lead to ∼ 31% higher tensile strength and approximately same electrical conductivity of the Cu matrix, while the GNPs-2–80/Cu composite only shows a ∼ 15% increase of tensile strength and a lower electrical conductivity than the Cu matrix. [ABSTRACT FROM AUTHOR]