Establishment and validation of an organic coating aging evaluation model based on analytic hierarchy process principle

There are various failure modes of organic coating protective systems and the accurate evaluation of their failure degree has attracted many attentions in recent years. In this study, on the basis of eight failure modes of organic coating protective systems, a comprehensively evaluating model was established using the Analytic Hierarchy Process (AHP) principle in conjunction with the Mean Square Error (MSE) method, and that the model was used to study the performance of the coated Al-alloy specimens coupled with Ti-alloy plates after accelerated tests. At the same time, the measurements of electrochemical Impedance Spectra (EIS) were conducted for the coated Al-alloy specimens subjected to accelerated tests. Finally, the mechanical properties of these coated Al-alloy specimens were investigated. The results showed that the higher the comprehensively evaluating values, the much more serious the failure degree of the organic coating protective system. The EIS results verified the comprehensive evaluation results obtained by this model for the coated Al-alloy specimens coupled with Ti-alloy plates after accelerated tests. In addition, it was found that the deterioration of the mechanical properties of the coated specimens was very related to the failure degree of these organic coating protective systems.