Fabrication and the mechanical and physical properties of nanocarbon-reinforced light metal matrix composites: A review and future directions

This paper presents a literature review on the fabrication process of nanocarbon-reinforced light metal matrix composites (LMMCs), where "nanocarbon" refers to carbon nanofibers (CNFs), carbon nanotubes (CNTs), and graphene nanoplatelets (GNPs). The review is focused on the structure and characteristics of the nanocarbon-light metal matrix interface. The amorphous structure or Al2O3 phase at the interface in CNT- or GNP-reinforced Al matrix composites leads to strong bonding and high-strength composites. Research on the interfacial reaction and structures of the Al-CNT system has shown that coating the reinforcement with the metal matrix is effective for the fabrication of composites with improved mechanical properties, and this approach has been demonstrated with Mg coatings. Depositing Ni or Cu to improve the interfacial properties in composites has been found to promote wetting by the matrix and improve properties of composites. On the basis of the coating treatments and interfacial modifications reviewed in this paper, a reinforcement mechanism for realizing high-strength and highductility composites is proposed. Future directions for the fabrication process to achieve superior mechanical and physical properties are also discussed.