Novel aluminum-graphene and aluminum-graphite metallic composite materials: Synthesis and properties

Article abstract of DOI:10.1016/j.jallcom.2015.12.084

A novel method of creating new lightweight, aluminum-metallic, composite materials under halides melt at temperatures 973-1073 K under air atmosphere is proposed. The method for synthesizing aluminum-based metallic composite materials, containing up to 2 wt. % graphene sheets uniformly distributed in a metal matrix, is entirely new, having no analogies in current science and practice. The synthesis of graphene nanosheets in a metal matrix is one-step, simultaneous process, taking place directly in molten aluminum under alkali halides melt without the necessity of a separate stage of synthesis and introduction of graphene. This has the potential to facilitate the inexpensive synthesis of aluminum-graphene composites with a high concentration of graphene. The aluminum-graphene composites formed according to this method are characterized by a high uniformity of graphene films with linear dimensions from 100 nm to 50 μm and a thickness from one to three nm in the metal bulk. No aluminum carbide forms under synthesis; the aluminum-graphene and aluminum-graphite composites are resistant to corrosion in NaCl solution. The hardness, strength and ductility of aluminum-graphene composites are at least 2-3 times higher than the initial aluminum material, proportional to the concentration of graphene.