Influence of graphene content on the microstructure and properties of GNPs/2024Al composites

In this study, reinforced 2024Al-based composites with different graphene nanoplatelets (GNPs) contents (0 %, 0.25 wt%, 0.5 wt%, 1 wt%, 1.5 wt%) were prepared by the Hot Pressed Sintering process method. The impacts of graphene content on its microstructure, mechanical properties and corrosion resistance were investigated using hardness test, tensile property test and intergranular corrosion property test. Furthermore, the microscopic mechanism was explored by combining scanning electron microscopy (SEM), XRD analysis and electrochemical analysis. It was demonstrated that with the increase of GNPs content, the strengthening effect of the composite showed a trend of increasing and then decreasing, and the best strengthening effect of 0.5 wt% GNPs/2024Al composite was achieved. When the solution and aging was 12 h, the hardness was 161.74 HV0.2 and the tensile strength was 476 MPa. The GNPs could reduce the anti-intergranular corrosion performance of 2024Al. As the content of GNPs increases, the corrosion current density of the composite gradually increases and the anticorrosion performance gradually decreases.