Improving mechanical properties and electrical conductivity of Al-Cu-Mg matrix composites by GNPs and sc additions

To enhance the mechanical properties and electrical conductivity of Al-Cu-Mg-based composites, aluminum matrix composites containing scandium (Sc) and graphene nanoplatelets (GNPs) were fabricated by means of stepwise ball milling, vacuum hot pressing sintering, and hot rolling techniques. When Sc and GNPs were incorporated at concentrations of 0.1 wt% and 0.2 wt% respectively, the resultant composites demonstrated a maximum tensile strength of 326.81 MPa, an elongation of 3.2%, an electrical conductivity of 46.95% IACS, and a hardness of 112.96 HV. In comparison with the 2024 aluminum alloy matrix, enhancements of 39%, 255%, 51% and 51.21% were witnessed in tensile strength, elongation, electrical conductivity, and hardness respectively. These improvements can be primarily ascribed to the addition of Sc, which facilitated the precipitation of solute atoms and enhanced the interfacial bonding between the GNPs and the matrix, as well as the remarkable heterogeneous layered microstructure induced by the incorporation of GNPs. This study presents a feasible approach to concurrently enhance the strength and electrical conductivity of composites through the combined addition of Sc and GNPs.