Preparation and properties of graphene nanoplatelets reinforced aluminum composites

5.0 vol.% graphene nanoplatelets (GNPs) and aluminum powders were mixed to prepare GNPs/Al composites via high-energy ball milling (HEBM). The mixed powders were subjected to spark plasma sintering (SPS) and subsequent hot extrusion. The microstructure and mechanical properties of extruded composites were investigated by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and tensile tests. In the extruded composites, 5.0 vol.% GNPs were dispersed homogeneously and no serious GNP−Al interfacial reaction occurred. As a result, the yield strength and ultimate tensile strength of the extruded GNPs/Al composites reached 462 and 479 MPa, which were 62% and 60% higher than those of the extruded Al matrix, respectively. The enhanced mechanical properties were attributed to the effective load transfer capacity of dispersed GNPs. This demonstrated that it may be promising to introduce dispersed high-content GNPs via HEBM, SPS and hot extrusion techniques and GNP−Al interfacial reaction can be controlled.