abstract
In this study, the corrosion resistance of AA2024-T3 specimens anodized in TSA and subsequently post -treated in a Ce-H 2 O 2 solution and sealed by a hybrid sol -gel coating (3-glycidoxypropyltrimethoxysilane and tetraethoxysilane), with hydrolysis solution aging times of up to 6 months, was investigated by means of electrochemical impedance spectroscopy (EIS). The results demonstrated that, whichever the aging time, the Ce post -treatment enhances the performance of the sol-gel coating; moreover, for both surface conditions, the corrosion protection was maximized for a hydrolysis time of 14 days, even though the corrosion performance of samples protected with the solution aged for 6 months was similar to that aged for 1 day. Correlation of these results with FTIR and viscosity measurements of the aged hydrolysis solution suggest that the protective performance of the coating is heavily influenced by in -solution condensation reactions; excessive condensation leads to the formation of oligomers, resulting in increasingly flawed coatings with specific delamination points as revealed by SEM imaging. The relatively long shelf life of the hydrolysis solution is a good prospect for the industrial use of the proposed treatment.
keywords
TARTARIC-SULFURIC ACID; HYBRID COATINGS; SILICA SOL; ALUMINUM; PROTECTION; OXIDE; MORPHOLOGY; SURFACE; FILMS; CE
subject category
Materials Science; Physics
authors
Ramirez, OMP; de Almeida, TF; Marin, JH; Suegama, PH; Starykevich, M; Ferreira, MGS; Ando, RA; de Melo, HG
our authors
Maksim Starykevich
Junior Researcher
Mário Guerreiro Silva Ferreira
Retired ProfessorProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
HG de Melo thanks Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-Brazil (FAPESP) Proc. 2018/01096-5 and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-Brazil (CNPq) Proc. 400895/2014-5 for the financial support to the project. O.M. Prada Ramirez thanks Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brazil (CAPES) Proc. 88887.388129/2019-00 and 88887.716342/2022-00. This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brasil (CAPES) -Finance code 001. M. Starykevich and M.G.S. Ferreira acknowledge the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) and M. Starykevich ac- knowledges the support of the FCT-2020.00625.CEECIND grant.