Effects of graphene content on microstructures and tensile property of graphene-nanosheets / aluminum composites

Abstract The graphene nanosheets (GNSs) reinforced Al matrix composites were successfully fabricated by high-energy ball milling and vacuum hot pressing. Effects of graphene content (0.25 wt%, 0.5 wt% and 1.0 wt%) on microstructures and tensile properties of GNSs/Al composites were investigated. Microstructures and the distribution of GNSs were analyzed with scanning electron microscope (SEM), X-ray diffraction (XRD) and transmission electron microscope (TEM). Tensile properties and hardness were studied at room temperature. The results show that the GNSs/Al composites with the high relative density and dispersed distribution of GNSs were fabricated. A good interfacial bonding was obtaned in GNSs/Al composites. The aluminum carbide Al 4 C 3 phases with granular and short rod-like morphology were found at interface. With the increase of GNSs content, the content of Al 4 C 3 phases increases. The dislocations were also found near the interface, and the density of dislocation reduced with the increase of Al 4 C 3 content. The Vickers hardness of GNSs/Al composites increases obviously with the increase of GNSs content. The yield strength and ultimate tensile strength of GNSs/Al composites have an obvious improvement compared to that of pure Al, but the elongation show a slight decrease. The yield strength and ultimate tensile strength of Al-0.25GNSs composites increase by 38.27% and 56.19% compare with that of pure Al. The GNSs pull-out is detected at the edges of dimples, and the number of dimples slight decreases with the increase of GNSs content.