2024-03-28T11:34:13Zhttps://www.tdx.cat/oai/requestoai:www.tdx.cat:10803/1348792017-09-22T04:43:54Zcom_10803_183col_10803_208
nam a 5i 4500
Revestimientos a base de sílica e ácido fosfônico para proteção anticorrosiva da liga de alumínio AA2024-T3
[Barcelona] :
Universitat Politècnica de Catalunya,
2014
Accés lliure
http://hdl.handle.net/10803/134879
cr |||||||||||
AAMMDDs2014 sp ||||fsm||||0|| 0 por|c
Dalmoro, Viviane,
autor
1 recurs en línia (151 pàgines)
Tesi realitzada en co-tutela (Universidade Federal do Rio Grande do Sul -Brasil- i Universtitat Politécnica de Catalunya)
Tesi
Doctorat
Universitat Politècnica de Catalunya. Departament d'Enginyeria Química
2013
Universitat Politècnica de Catalunya. Departament d'Enginyeria Química
Tesis i dissertacions electròniques
Alemán, Carlos,
supervisor acadèmic
Schermann Azambuja, Denise,
supervisor acadèmic
Santos, João Henrique Zimnoch dos,
supervisor acadèmic
TDX
The aluminum alloy AA2024-T3, u sed extensively in the aerospace industry, dueto the heterogeneous microstructures
intentionally designed to optím ize the m echanical properties, is very susceptible to localízed corros ion. In order to preven! the
corros ion several surface treatments have been investigated to replace the chromate treatment and, in thís way, sílica based
films can be regarded as a promising alternatíve.
The aim ofthis work ís the obtaíníng, development and characterízation offilms vinyltrímethoxysilane (VfMS) combíned wíth
tetraethylorthosílícate (TEOS) or y-glycídoxypropyltrímethoxysílane in the presence and absence of ethylenedíamíne
tetrametílene phosphoníc a cid (EDTPO) as pretreatments agaínst corros ion of alumínum alloy AA2024-T3 in NaCI 0.05 mol
L-1. Furthermore, ít was investígated the effect of addíng clayto sol-gel hybríd matríx and sílica nanoparticles to the matrix of
VfMS/GPTMS films containing EDTPO. Different ratios of precursor and silica concentrations of phosphonic acid andel ay
were evaluated. The anticorrosíve properties ofthe alloycoated with the modífied sílíca films were studied using
electrochemical impedance spectroscopy (El S) after different immersion times. The chemical structure ofthe films and the
starting solutíons were characterízed by ínfrared spectroscopy (FT-IR), whíle the morphology and com posítion of the film s
were examíned on usíng Scanníng Electron Microscopy (SEM), Energy Dispersive Spectroscopy X-Ray (E O X) and 1 or
Photoelectron Spectroscopy X-Ray (XPS). The results obtained were posítive for the corros ion protectíon of AA2024 using the
coatings obtaíned by the sol-gel method and modífied with phosphonic a cid.
Mer optimization ofthe coatings of silica and silica/phosphonic acid we applied !he bes! systems as anticorrosíve
pretreatments and adhesion promoters for one epoxy primer paínt. Accelerated corros ion tests allowed check the beneficia!
action ofthe silica layer as anchoring system for the epoxy paint. lt was found that the systems composed by: silica/epoxy
paint and silica + phosphonic acid/epoxy paint and silica/ epoxy paint modified with conducting polymer provide effective
corros ion protection for the alloy AA2024-T3.
The results deríved from the present thesis have been accepted or have been sent for publicatíon in ínternational journals
and also reported in sorne international congresses, as we point below:
[1] V. Dalmoro, J . H. Z. dos Santos, E. Armelin, C. Alemán, O. S. Azambuja, Phosphonic acid/silica-based films: A potential
treatm en! for corros ion protection, Corros. Sci. 60 (2012) 173-180.
[2] V. Dalmoro, J. H. Z. dos Santos, E. Armelín, C. Alemán, D. S. Azambuja, A synergistic combination oftetraethylorthosilicate
and multiphosphonic acid offers excellent corros ion protectíon to AA1100 aluminum alloy, Appl. Surf. Sci . 273 (2013)
758-768.
[3] V. Dalmoro, J . H. Z. dos Santos, l. M. I.M. Baibich, E. Armelin, C. Alemán, O. S. Azambuja Cooperatíve effect between
VfMS/TEOS and phosphonic acid for corros ion protection of AA2024, Submitted, 2013.
[4] V. Dalmoro, J. H. Z. dos Santos, E. Armelín, C. Alemán, D. S. Azambuja, Organosílane and Montmorílloníte-based hybríd
films produced by sol-gel: A potencial treatrnent for corros ion of AA2024, Manuscript on preparation, 2013.
[5] V. Dalmoro, J. H. Z. dos Santos, E. Armelin, C. Alemán, D. S. Azambuja, Characterization ofTEOS/phosphoníc acíd films,
63rd Annual Meeting of lnternatíonal Socíety of Electrochem ís try 19-24 August 2012, Prague, Chech Republíc
p
ES-BaCBU
cat
rda
ES-BaCBU
text
txt
rdacontent
informàtic
c
rdamedia
recurs en línia
cr
rdacarrier