In-situ synthesis of graphene on surface of copper powder by rotary CVD and its application in fabrication of reinforced Cu-matrix composites

摘要

A novel approach has been developed for fabricating graphene (Gr) reinforced Cu composites. First, graphene was synthesized in-situ on surface of micron-sized copper powder through rotary chemical vapor deposition (RCVD). Then, the composite powders were hot pressed into bulk Gr-Cu composite pieces in vacuum. During RCVD, methane flow rate controlled the number of layers in synthesized graphene. Analyses of Raman spectroscopy suggested that graphene with varied layer numbers were formed on Cu powder surface. The as-fabricated graphene exhibited a 'wrinkle' type morphology with a homogeneous distribution observed by field emission scanning electron microscopy (SEM). After hot pressing, the structure and morphology of graphene were preserved in the Gr-Cu bulk composites, as confirmed by high-resolution transmission electron microscopy (HRTEM). Physical and mechanical properties of these bulk composites were studied. They were nearly fully densified and featured with an increase of more than 30% in hardness, as well as similar electrical conductivity and thermal conductivity as compared with pure Cu. The mechanism therein was discussed.