Architectured interfacial interlocking structure for enhancing mechanical properties of Al matrix composites reinforced with graphene nanosheets

Abstract

The robust interface adhesion between matrix and reinforcement is the guarantee for enhancing mechanical performance of the metal matrix composites (MMCs). Unfortunately, the low strengthening efficiency and drastically reduced elongation have always been the cases for MMCs due to the difficulties for architecting tightly-bonded and effective interface structure. Herein, a new strategy is proposed to construct interfacial interlocking structure in the Al matrix composites reinforced by graphene nanosheets (GNS) decorated with Ni nanoparticles (Ni NPs@GNS), which were in-situ synthesized by using assembled NaCl particles as templates. The hybrid particle of Al3Ni and Ni serves as an interface interlocking factor to fasten the bonding of Al and GNS, thus the outstanding load transfer and dislocation accumulation capability are adequately achieved at the interfaces. Besides, experiments and first-principles calculations disclosed that the robust covalent bonding between Ni NPs and GNS with few defects and lower oxygen level synthesized in this work facilitates a tortuous crack propagation path before fracture. Hence, the as-obtained composites exhibited an excellent strengthening efficiency while preserving a good ductility. It is evidenced that the construction of interfacial interlocking structure can pave a promising path to produce strong, tough and lightweight MMCs for wide applications.