This study aims to facilitate the selection of an appropriate zinc-rich coating formulation, which remains challenging, particularly given the wide range of zinc-rich paints available. Therefore, the authors proposed a robust approach to produce an optimal zinc-rich epoxy (ZRE) coating. This strategy aims to use optimization techniques in conjunction with model reduction. This approach is based on the percentages of zinc, silica, epoxy and vinyl, and the immersion time in 3.5% NaCl, as decision variables to maximize anti-corrosion performance.
Electrochemical Impedance Spectroscopy (EIS), Open Circuit Potential (OCP) measurements and X-ray diffraction (XRD) patterns of the corrosion products were used to characterize the anticorrosion properties of each ZRE paint formulation, generating a comprehensive data set to support optimization procedures. Accordingly, the Proper Orthogonal Decomposition combined with the Radial Basis Function (POD-RBF) approach, in addition to Exponential Trigonometric Optimization (ETO) and Cuckoo Search (CS) algorithms, were used to perform the optimization.
The results confirm that all 11 formulations exhibit both sacrificial cathodic protection and a barrier effect, mainly governed by zinc oxidation. Furthermore, silica and vinyl resin reduce excessive zinc consumption and enhance barrier performance. ETO is an efficient and feasible methodology for predicting the best ZRE coating with the best anti-corrosion property, compared to CS.
This study introduces an original synthesis of the anticorrosion behavior of zinc-rich coatings by jointly varying pigment and resin compositions. Coupling anticorrosion analysis with optimization and inverse-problem approaches enables the direct prediction of coating formulations that meet targeted corrosion performance, while reducing the number of experiments required.
