STUDY OF AN ALUMINUM-BASED NANOCOMPOSITE REINFORCED WITH CARBON NANOTUBES

In this work, the effects related to the improvement of the mechanical characteristics of 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 con-sidered. The values of 4.3 meV/angstrom(2) and 18.1 meV/angstrom(2) respectively, were obtained, which are compa-rable 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, depend-ing on the surface type and armchair or zigzag shear direction. The influence of carbon mon-ovacancies on mechanical properties of the composite was studied. Critical shear stress values of 1500-2000 MPa were obtained for energetically advantageous configurations of composites, de-pending 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 similar to 10(3) MPa.

Automated summary

In this study, the effects of carbon nanotube reinforcement on the mechanical properties of aluminum-based nanocomposites were investigated using computational calculations. The results showed that the energy of the graphene/aluminum interface significantly influenced the material properties, and the presence of defects and surface type affected the critical shear stress. Furthermore, embedding small diameter carbon nanotubes increased the binding energy and improved the critical stress values.