Aluminum Matrix Composites Reinforced with Graphene: A Review on Production, Microstructure, and Properties

Abstract Graphene, a single-atom-thick sheet of sp2 hybridized carbon atoms densely packed within a hexagonal crystal lattice, owes a significant portion of its rapidly expanding usage in various fields of industry and science to its large surface area, lightweight, unique electronic and thermal properties, and extraordinary mechanical properties that it possesses. Using lightweight and high-strength materials leads to a substantial decrease in fuel consumption as well as an increase in payload. Among the numerous candidates to fulfill the aforementioned requirements, Al alloys and specifically, Al matrix composites (AMCs) reinforced with various graphene particles (nano-sheets, nano-platelets, etc.) stand out owing to their inherent lightweight, high specific strength and modulus, superior ductility and excellent thermal conductivity. In this paper, it has been endeavored to provide a comprehensive overview of the various methods of the synthesis and fabrication of graphene-reinforced AMCs with an overall intention of achieving a homogeneous distribution of graphene within the Al matrix. The emphasis of this review has been largely placed upon the detailed examination of the mechanical properties of these composites described in the recent literature published in this field. The strengthening mechanisms of Al/graphene composites, as well as the parameters affecting the strength and ductility achieved by graphene, such as the agglomeration of graphene within the Al matrix and Al/graphene interfacial reactions, have been elucidated. The role of graphene on the electrical and thermal properties of graphene-reinforced AMCs and the directions for future research are addressed. It should be noted, however, that while a diligent analysis of various works published in the field of Al/graphene composites has been carried out in this review, an exact comparison between the varying stages of each work, or their final properties is impractical, mainly due to the differences in the used initial substances, processing, and analyses.