Enhanced mechanical and electrical performance of graphene oxide–reinforced AA 1020 aluminum nanocomposites fabricated via hot accumulative roll bonding

Abstract

Graphene-reinforced aluminum composites combine high strength with attractive electrical performance for advanced structural and functional uses. In this work, AA 1020 aluminum (hereafter abbreviated as AA 1020 Al) sheets were processed by hot accumulative roll bonding (ARB) at 380°C with 50% thickness reduction per pass, while a graphene oxide (GO) emulsion was interlayer sprayed prior to rolling to fabricate GO/Al laminates. After four passes, the composite achieved 37.1% higher tensile strength than the unprocessed sheet and 6.0% higher strength than preheated ARB AA 1020 without GO at the same pass, together with improved elongation and strain energy density. Optical microscopy, combined with image-based gray-scale intensity analysis, showed that increasing the number of passes promoted a more uniform through-thickness GO distribution; 15 GO-rich planes were detected after four passes, consistent with ARB interface multiplication. Electrical resistance measurements indicate that hot ARB increased the resistance of unreinforced AA 1020 Al sheets, primarily because process-induced defects (dislocations, grain boundaries) and interfacial oxide layers increase electron scattering and contact resistance. Incorporation of GO lowered measured resistance relative to unreinforced hot-ARB sheets across passes (largest drop at Pass 1), consistent with improved interlayer connectivity and the formation of conductive pathways. These results demonstrate that hot ARB provides a scalable route to graphene oxide–reinforced AA 1020 Al with a favorable balance of strength, ductility, and electrical performance.