Characterization of the Microstructure and Mechanical Properties of a Novel Functionally Graded Material Based on Al–Zn–Cu–Mg Alloy Matrix Reinforced with Few-Layered Graphene

Abstract

Composite materials satisfactorily suit the needs of industrial applications. However, with the advancement of modern technology, functionally graded materials (FGMs) are becoming increasingly important in order to meet evolving customer demands. The reinforcement material in FGMs varies in quantity and arrangement across different regions, resulting in continuously changing properties and a non-uniform microstructure. Various industries widely employ aluminum (Al) alloys due to their favorable features, which include excellent stiffness, ductility, a high strength to weight ratio, and corrosion resistance. The current study facilitates the powder metallurgy (P/M) production of a novel generation of a six-layer Al–Zn–Cu–Mg alloy material graded according to increasing few-layered graphene (FLG) reinforcement. The increase in the FLG content between the layers, from the first to the last layer, results in an increase in the hardness value (HV) of the FGM by ≈39.13%. The most effective strengthening mechanism for FGM is grain size reduction, which is a result of the FLG content present in each layer. Moreover, the load transfer and reinforcing effect of graphene are enhanced by the strong interface bond that occurs between FLG and the matrix.