Effect of process parameters and film stratification on morphology and performance of auto-lubricating Ni-GnP electroplated coated steel

Metal-matrix composites are of increasing interest in various industrial fields. The graphene reinforcement phase within the metal matrix structures makes it possible to enhance their properties and, thus, their performance in many contexts of use. Nickel is one of the most widely used materials to create such composites due to its mechanical and anti-corrosive qualities. In particular, many nickel and graphene coatings are produced by electrodeposition. Despite being an extremely mature process, the production of composite coatings is not trivial, as the morphology of the film and the graphene inclusion and distribution within the bulk depends on different process parameters. The work aims to produce a self-lubricating composite coating of nickel and graphene nanoplatelets. Based on an initial implemented process, the layering of the layers coated and the mechanical agitation of the bath were varied to improve the inclusion of graphene in the matrix. The results showed that coating morphology is strongly affected by the process; also, an increment of film roughness and homogeneity does not necessarily translate into an increase in performance.