Yolshina L.A., Muradymov R.V., Molchanova N.G.
ABSTRACT
Corrosion resistance of aluminum-graphene and aluminum-graphite composites, which were synthesized by chemical interaction of fused aluminum with boron carbide under molten alkali and alkali-earth halogenides layer under air at 700–800°С, in 3% NaCl aqueous solution at room temperature. Aluminum-carbon composites produced by the proposed method are compact and non-porous, with a characteristic metallic shine and good electrical conductivity. The carbon content of the composites is consistent from the surface of the aluminum drop to its center. No aluminum carbide forms at synthesis of aluminum-carbon composites. Even small amounts of aluminum carbide in aluminum materials dramatically deteriorate corrosion resistance. The formation of uniformly distributed graphene films and graphite crystals in aluminum matrix confirmed by Raman spectroscopy. Corrosion rate of both composites is more that initial aluminum one increasing with the increasing of carbon content in them. Class corrosion resistance of aluminum—3 (resistant) and aluminum composites—4 (rather persistent) in NaCl solution. The corrosion rate of the aluminum-graphite composite is approximately 3 times higher than that of the aluminum-graphene composite with an equal carbon content. It is shown that the corrosion of the aluminum-graphite composite is non-uniform, pitting is formed around the graphite crystals because of the big difference in the standard potentials of carbon and aluminum. The corrosion of the aluminum-graphene composite is uniform; the layer of aluminum monoxide forms, which confirmed by XRD.
KEY WORDS
aluminum, graphene, graphite, Raman spectroscopy, metal-matrix composite, synthesis, corrosion, pitting, aluminum monoxide
DOI: 10.31857/S0235010621060037