Evolution of microstructure and mechanical properties of graphene oxide-reinforced aluminum alloy (6061) composite fabricated via accumulative roll bonding

This study investigates the fabrication and characterization of Al alloy matrix composites reinforced with graphene oxide (GO) using accumulative roll bonding (ARB). The annealed Al 6061 sheets were processed through 5-pass ARB with GO reinforcement applied during the initial passes. Scanning electron microscopy revealed effective mitigation of GO agglomeration and improved interface bonding due to microscale material mixing. Raman spectroscopy confirmed the strong interaction between GO and the Al alloy matrix, as evidenced by the increased D band intensities and enhanced 2D band symmetry. Mechanical testing indicated an approximately 338.37% increase in yield strength (YS) and 86.42% improvement in hardness for the ARB-processed (ARBed) Al 6061/GO composite (0.2wt%) compared with annealed Al 6061 and an approximately 14.15% increase in YS and 17.23% improvement in hardness for the ARBed Al/GO composite (0.2wt%) compared with unreinforced ARBed Al 6061 specimens after five passes. X-ray diffraction analysis indicated an increased dislocation density, corroborating the observed enhancements in mechanical properties. Fracture surface analysis revealed reduced elongation with deep dimples, highlighting the tradeoff between strength and ductility. These results demonstrate the effectiveness of ARB for integrating GO into the Al 6061 matrix to improve the mechanical performance and interfacial bonding and underscore its potential for advanced composite materials.