Active and passive protection of AA2024-T3 by a hybrid inhibitor doped mesoporous sol–gel and top coating system
Autor: | Yaiza Gonzalez-Garcia, Philippe Dubois, Farid Khelifa, Johannes M. C. Mol, Marie-Georges Olivier, Isaline Recloux, Marie-Eve Druart |
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Rok vydání: | 2016 |
Předmět: |
Materials science
2024 aluminium alloy 02 engineering and technology engineering.material 010402 general chemistry 01 natural sciences Corrosion chemistry.chemical_compound Scanning electrochemical microscopy Coating Materials Chemistry Thin film Polarization (electrochemistry) Benzotriazole Metallurgy Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Surfaces Coatings and Films chemistry Chemical engineering engineering 0210 nano-technology Mesoporous material |
Zdroj: | Surface and Coatings Technology. 303:352-361 |
ISSN: | 0257-8972 |
Popis: | In the present investigation, a two-layer coating system was developed in order to protect 2024 aluminium alloy against corrosion. At the metal interface, a silica mesoporous thin film was used to offer storage and release functionalities for benzotriazole inhibitive molecules (active protection). An acrylic top coat was then applied as a barrier layer against corrosive species (passive protection). Various electrochemical techniques were employed to evaluate the anticorrosion performance of the coating system. Amongst them, the scanning vibrating electrode technique (SVET) and the scanning electrochemical microscopy (SECM) showed a slowdown of corrosion processes occurring within the damaged coating area. The acquisition of anodic polarization curves inside the scratch through the use of an electrochemical micro-cell allowed to correlate this enhancement in the corrosion protection with the formation of an inhibitive film. Upon a through-coating damage, the mesoporous reservoir comes into contact with the aggressive electrolyte and benzotriazole molecules are able to be released and to inhibit corrosion of the bare metal exposed in the scratch. The work demonstrates the potential of mesoporous films as reservoir for inhibitive species and its efficiency for controlled release of the inhibitor. Furthermore, the work demonstrates the added value of electrochemical micro-cell measurements to highlight active corrosion protection in coating defects due to inhibitor doped coating systems. |
Databáze: | OpenAIRE |
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