Graphene-Reinforced Bulk Metal Matrix Composites: Synthesis, Microstructure, and Properties

Abstract

This paper provides a critical review on the current status of graphene-reinforced metal matrix composites (GRMMCs) in an effort to guide future work on this topic. Metal matrix composites are preferred over other types of composites for their ability to meet engineering and structural demands. Graphene is considered an ideal reinforcement material for composites due to its unique structure and extraordinary physical, thermal, and electrical properties. Incorporating graphene as a reinforcement in metals is a way of harnessing its extraordinary properties, resulting in an enhanced metallic behavior for a wide variety of applications. Combining graphene with bulk metal matrices is a recent endeavor that has proven to have merit. A systematic study is needed to critically examine the efforts applied in this field, the successes achieved, and the challenges faced. This review highlights the three main pillars of GRMMCs: synthesis, structure, and properties. First, it discusses the synthesis techniques utilized for the fabrication of GRMMCs. Then, it highlights the resulting microstructures of the composites, including graphene dispersion and interfacial interactions. Finally, it summarizes the enhancements in the mechanical, electrical, thermal, and tribological properties of GRMMCs, while highlighting the effects of graphene type and content on those enhancements.

Effect of Silicon Nitride and Graphene Nanoplatelets on the Properties of Aluminum Metal Matrix Composites

“…Furthermore, the density of the composites is found to decrease with the increasing amount of GNPs due to an incremental decrease in the density of the Al matrix due to its replaced amount by GNPs. A similar trend in the density results was noticed in a previous study conducted on Al-Graphene composites [ 10 , 17 ]. For a deeper insight into the density behavior of the composites, relative density ( ) of the developed composites was determined using the actual or measured density ( ) and the theoretical density values ( ) as indicated in the below Equation [ 31 ].…”

“…It can be observed that the hardness and Young’s modulus of Al-Si 3 N 4 -GNPs composites increase with increasing concentration of GNPs. Such behavior is attributed to the presence of GNPs having a positive influence in improving the mechanical properties of pure Al [ 6 , 17 ]. Besides, the presence of hard crystalline Si 3 N 4 nanoparticles has also contributed to improving the hardness of the pure Al matrix [ 36 ].…”

“…The presence of pores due to GNPs agglomerates or overlapping of GNPs leads to crack initiation during the compressive loading and hence adversely affects the compressive strength of the developed composites. Another reason is due to the lubricating nature of graphene which triggers the graphene sheets to slide easily under compression loading, hence, it reduces the friction between hard ceramic particles of Si 3 N 4 allowing it to slide during the plastic deformation region under compressive loading which leads to a degradation in the compressive strength [ 17 ]. Additionally, the weak Van der Waals force between the graphene sheets enhances the shifting of the sheets under applied loading which in turns decreases the compressive strength [ 46 ].…”

“…Among these techniques, the ball milling process has attracted wide attention for its considerable impact on the microstructure of the product. Once utilized at the optimum operating conditions that conform with the feed material, it produces homogeneously distributed reinforcements within the metal matrix by enhancing the affinity between the reinforcement and the matrix [ 17 ].…”

Pure-silk fibroin hydrogel with stable aligned micropattern toward peripheral nerve regeneration

“…Previously, it was also found that anisotropic bridge microstructure can regulate the morphology and biological function of Schwann cells [13]. The synthetic matrix showed extraordinary physical properties to meet microstructural demands [14]. Synthetic hydrogel-based materials with the micro-groove structure on the surface can also effectively regulate the migration and oriented growth of Schwann cells [15].…”