Applied Surface Science, Vol.457, 1072-1080, 2018
MD-based estimates of enhanced load transfer in graphene/metal nanocomposites through Ni coating
In this research, the effects of graphene coating on the load transfer issue occurred in the interfacial zone of copper-based nanocomposites are examined employing molecular dynamics (MD) simulations. To this end, first, four different cases, i.e. pure graphene, pristine copper, uncoated and Ni-coated graphene/copper samples are examined under uniaxial tensile loading. These studies are conducted to explore the reinforcement role of graphene sheets and also to tune the necessary parameters implemented in simulations. The results reveal that addition of only 5% volume fraction of graphene, leads to an enhancement of 34.9% and 47.2% in the Young modulus of the base copper infused with non-treated and coated graphene, respectively. Subsequently, utilizing the confirmed model, pull-out tests are performed to capture the influence of interfacial bond strength on the load transfer in Cu/graphene samples. Finally, to find out the role of graphene coating with metals having stronger interactions with this carbon nanostructure, the pull-out numerical experiments are repeated in the presence of different percentages of nickel coating. It is demonstrated that at various amounts of 50, 75, and 100 percent Ni coating, the average interfacial shear stress in graphene/Cu samples can be enhanced up to 99%, 458%, and 707%, respectively. In summary, such a process provides a practical route for improving the load transfer efficiency in copper-based nanocomposites reinforced with graphene sheets.
Keywords:Molecular dynamics simulation;Metal matrix nanocomposite;Graphene;Pull-out test;Interfacial interaction;Nickel coating