Effect of Deposition Parameters for Ni-Au Coatings on Corrosion Protection Properties of 2A12 Aluminum Alloy

The Ni-Au coating with its inherent chemical stability is recognized as an effective method for boosting corrosion resistance in humid environments while preserving exceptional electrical conductivity. However, its anti-corrosion performance is affected by the structure characteristics of the coating due to the high corrosion potentials of Au and Ni. To enhance its protection properties, the deposition process parameters, including deposition time, deposition current density, and zincating times, were investigated. The morphology and structure of the coatings were characterized, while its anti-corrosion performance was assessed through electrochemical and accelerated salt-spray tests. Eventually, the elevated current density in the Ni-Au coating resulted in reduced grain size and improved surface morphology, ensuring superior anti-corrosion performance. Additionally, extending the Ni deposition time provided a second physical barrier for the dense and thick Ni layer to resist the invasion of corrosive media. Furthermore, grey theory was applied to predict the service life of the Ni-Au coating. This research provides valuable insights and constructive guidance for optimizing Ni-Au coating in various engineering applications.