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Electrochemical testing practices of environmentally friendly aerospace coatings for corrosion performance assessment
Author(s) -
Kefallinou Zoi,
Zhou Xiaorong,
Curioni Michele
Publication year - 2019
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.6605
Subject(s) - corrosion , aerospace , environmentally friendly , coating , dielectric spectroscopy , materials science , immersion (mathematics) , conversion coating , hexavalent chromium , process engineering , metallurgy , engineering , nanotechnology , electrochemistry , chromium , aerospace engineering , ecology , chemistry , mathematics , electrode , pure mathematics , biology
Hexavalent chromium has been successfully employed for corrosion protection purposes in aerospace coatings for decades. However, legislation will restrict the use of Cr 6+ in the future and therefore the aerospace sector needs to identify alternative environmentally friendly coatings for corrosion protection. Before implementation of newly developed systems into actual components is possible, rigorous and time‐consuming testing practices are required to ensure the new systems can achieve the strict aerospace standards requirements. The emerging number of coating systems being developed, and the vast research conducted on the subject worldwide, make the selection of suitable replacements for industrial application challenging. In this work, differently pretreated aluminium AA2024 alloy surfaces are coated with conventional Cr 6+ containing coating and compared with a number of industrial alternative coatings. Corrosion performance is assessed by real‐time imaging while immersed, by electrochemical impedance spectroscopy (EIS), and by standardised salt‐spray testing (SST). Results reveal that the performance ranking acquired by SST can be readily replaced by short‐term immersion tests, and the time to failure in SST can be estimated from key corrosion indicators arising from EIS measurements at specific immersion times.