▎ 摘　　要

It is quite difficult to in situ synthesize graphene economically and directly onto surfaces of copper powders as a reinforcement phase for metal matrix composites, and few studies have been focused on interfacial bonding characteristics between graphene layer and copper powders. This paper explores a new strategy using wheat flour as a precursor to in situ generate graphene on the surfaces of copper powders and investigates interfacial bonding characteristics between graphene and copper powders. Results reveal that the in situ generation process of graphene on the surfaces of copper powders has two critical stages. The first one is the low-temperature stage (up to 400 degrees C), in which H-2 reduces the oxide layer (Cu2O) into metallic Cu on the surfaces of the copper powders. The second one is the high-temperature stage (from 289 to 800 degrees C), in which the copper powders, with their good catalytic properties, cause the breakup of chemical bonds of the flour and expose the carbon atoms, and then high affinity of copper and carbon atoms causes recombination of carbon atoms and formation of graphene. Interfacial structures of the graphene-coated copper composite powder show semi-coherent features with a lattice matching of graphene({002}) / /Cu-{111}. The interfaces between Cu and graphene have not shown any intermediate phases or porous structures. These composite powders produced using such a low-cost but highly efficient process can be effectively used as an excellent reinforcement for metal matrix composites. [GRAPHICS]