Deposition of graphene-copper composite film by cold spray from particles with graphene grown on copper particles

Graphene has been used to improve tribological property due to its extraordinary properties. For graphene composite, obtaining uniformly distributed and less damaged graphene is important for better improvement. In this research, graphene was fabricated on copper particle by thermal chemical vapor deposition to minimize structural damage and obtain uniform distribution. The obtained graphene-coated copper composite particle was deposited by cold spray which is less deteriorative for graphene. The scanning electron microscope images show that graphene appeared to surface of copper particle without any agglomeration. Raman spectrum indicates that mostly monolayer graphene was obtained. Uniform distribution of graphene was observed after the deposition by cold spray. Furthermore, the deposition by cold spray induced neglectable structural damages on graphene. Nevertheless 0.019 wt% of carbon corresponding to graphene was incorporated in the composite film, graphene improved tribological properties in comparison with those of the copper film; the average friction coefficient values were 0.60 and 0.46 for the copper and composite films, respectively, and the calculated specific wear rates of the films were 8.6 x 10-4 and 5.2 x 10-4 mm3/N center dot m for the copper and graphene-copper composite films, respectively. The improved tribological properties resulted from the low shearing and passivation film by the incorporated graphene.