resumo
An active protective coating for ZE41 magnesium alloy was produced by sealing an anodic layer, loaded with 1,2,4-triazole, with a sol-gel film. An anodic oxide layer was formed using PEO in a silicate-fluoride alkaline solution. This thin (1.8 mu m) porous PEO layer was impregnated with corrosion inhibitor 1,2,4-triazole and sealed with a silica-based sol-gel film modified with titanium oxide. For the first time it was demonstrated that this relatively thin PEO-based composite coating revealed high barrier properties and provided superior protection against corrosion attack during 1 month of continuous exposure to 3% NaCl. A scanning vibrating electrode technique showed a sharp decrease (100 times) of corrosion activity in micro defects formed in the 1,2,4-triazole doped composite coating, when compared to blank samples.
palavras-chave
PLASMA ELECTROLYTIC OXIDATION; AZ31 MG ALLOY; COMPOSITE COATINGS; RESISTANCE; AA2024; FILMS; IMPROVEMENT; CONVERSION; LAYER
categoria
Chemistry
autores
Ivanou, DK; Yasakau, KA; Kallip, S; Lisenkov, AD; Starykevich, M; Lamaka, SV; Ferreira, MGS; Zheludkevich, ML
nossos autores
Aleksey Lisenkov
Investigador
Kiryl Yasakau
Investigador Auxiliar
Maksim Starykevich
Investigador Júnior
Mário Guerreiro Silva Ferreira
Professor(a) Jubilado(a)
Mikhail Zheludkevich
Investigador Principal Convidado
Silvar Kallip
Investigador AuxiliarProjectos
Fault-tolerant anticorrosion coatings for magnesium alloys (PTDC/CTM-MET/112831/2009)
RMNE-UA-National Network of Electron Microscopy (REDE/1509/RME/2005 )
agradecimentos
Portuguese Foundation for Science and Technology (FCT), project Fatomag, PTDC/CTM-MET/112831/2009. The financial support of FCT in frame of REDE/1509/RME/2005 project is gratefully acknowledged. K. A. Yasakau thanks FCT for Post-Doctoral grant (ref. SFRH/BPD/80754/2011). Airbus Group Innovations, Munich, Germany for supplying the alloys. S. Kallip thanks FCT for grant IF/00856/2013. S. V. Lamaka thanks the Alexander von Humboldt foundation for financial support of her Experienced Researcher grant.