STUDY OF AN ALUMINUM-BASED NANOCOMPOSITE REINFORCED WITH CARBON NANOTUBE

Abstract

aluminum-based nanocomposites reinforced with carbon nanotubes were studied by computational calculations. Numerical simulations were performed within the framework of density functional theory using the plane wave basis set implemented in VASP software package. Non-local van der Waals functional was used to describe. For modeling of aluminum-based composites with large-diameter nanotubes the limiting case of the interface of the graphene/aluminum species was considered. The values of 4.3 meV/Å2 and 18.1 meV/Å2 respectively, were obtained, which are comparable with the van der Waals interaction energies by order. It is also obtained that the critical shear stress value for the defect-free graphene/aluminum system varies from 20 MPa to 70 MPa, depending on the surface type and "armchair" or "zigzag" shear direction. The influence of carbon monovacancies on mechanical properties of the composite was studied. Critical shear stress values of 1500-2000 MPa were obtained for energetically advantageous configurations of composites, depending on defect location, surface type and shear direction. The formation energies of the defects were determined. Finally, the alumina matrix composites with small diameter embedded carbon nanotubes are considered. It is shown that with a decrease in the size of the nanotube its surface curvature is observed and, as a consequence, the binding energy at the interface with the metal matrix is increased. Calculated values of critical stress reach values of the order of ~103 MPa.