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

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.