GNPs/Al nanocomposites with high strength and ductility and electrical conductivity fabricated by accumulative roll-compositing

Aluminum matrix composites (AMCs) reinforced with graphene nanoplatelets (GNPs) were fabricated by using an accumulative roll-compositing (ARC) process. Microstructure, mechanical and electrical properties of the nanostructured AMCs were characterized. The results showed that small addition (0.2 vol% and 0.5 vol%) of GNPs can lead to a simultaneous increase in the tensile strength and ductility of the GNPs/Al nanocomposites, as compared with the same processed pure Al. With increasing GNPs content, the tensile strength of the GNPs/Al nanocomposites can be enhanced to 387 MPa with retained elongation of 15%. Meanwhile, the GNPs/Al nanocomposites exhibited a good electrical conductivity of 77.8%-86.1% that of annealed pure Al. The excellent properties (high strength, high ductility and high conductivity) of the GNPs/Al are associated with the particular ARC process, which facilitates the uniform dispersion of GNPs in the matrix and formation of ultrafine-grained Al matrix. The strengthening and toughening of the GNPs/Al nanocomposites were discussed considering different mechanisms and the unique effect of GNPs.