Abstract
This study was focused on the synthesis and characterization of Si/Zr-based hybrid sol-gel coatings with and without the addition of cerium(III) ions. The coatings were deposited on aluminum aiming to act as an effective and ecologically harmless alternative to toxic chromate coatings. The chemical composition, structure, thermal properties and porosity of the non-doped and Ce-doped coatings containing various Zr contents were examined by Raman spectroscopy and photothermal beam deflection spectroscopy. The corrosion properties of the coated aluminum substrates were studied using AC and DC electrochemical methods in 0.1 M NaCl electrolyte solution. Barrier and protecting properties of the coatings were monitored upon long-term immersion in chloride solution using electrochemical impedance spectroscopy. The effect of cerium ions was two-fold: on the formation of a more condensed Si−O−Zr network structure and on the formation of Ce-based deposits, which diminish the rate of cathodic reaction at the coating/metal interface. These effects acted synergistically and resulted in the creation of the coatings with effective barrier and active corrosion protection.
Highlights
Aluminum (Al >99.0%) is commonly used for numerous commercial applications due to its physical and chemical characteristics
The present work aims at producing hybrid TMZ sol-gel coatings with different amounts of zirconium tetrapropoxide with and without the addition of cerium ions to obtain better barrier, as well as active corrosion protection of aluminum
The first silicon-based sol was prepared by mixing tetraethyl orthosilicate (TEOS) and MAPTMS, and the second sol, containing zirconium, was obtained by the addition of methacrylic acid (MAA) to the ZTP
Summary
Aluminum (Al >99.0%) is commonly used for numerous commercial applications due to its physical and chemical characteristics. The mechanical and corrosion coating properties of similar Si/Zr-based sol-gel systems have been investigated on aluminum alloys [18,20,21,22,23]. Such coatings present only barrier corrosion protection without active corrosion inhibition [18]. The present work aims at producing hybrid TMZ sol-gel coatings with different amounts of zirconium tetrapropoxide with and without the addition of cerium ions to obtain better barrier, as well as active corrosion protection of aluminum. Self-healing properties of the Ce-doped coatings were observed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
