Corrosion performance of anodic films containing polyaniline and TiO2 nanoparticles on AA3105 aluminium alloy

Zubillaga, Oihana; Cano, Francisco; Azkarate, I.; Молчан, И. С.; Thompson, G.E.; Cabral, Ana M.T.D.P.V.; Morais, Paulo

doi:10.1016/j.surfcoat.2008.06.169

Cited by 52 publications

(21 citation statements)

References 25 publications

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“…12 Further, the alloys treated with PreCoat A32 pretreatment showed impedance modulus slightly higher than the alloys treated with Alodine 1200 for longer immersion times. PreCoat A32 pretreatment onto AA2024-T81 shows a separation of the two time constants.…”

Section: Impedance Measurementsmentioning

confidence: 89%

Alternative corrosion protection pretreatments for aluminum alloys

et al. 2017

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Aluminum alloys are extensively used in space programs for both structural and nonstructural applications. As is well known, the corrosion resistance of these alloys is quite limited and anticorrosion treatment is needed. Currently, the treatment most often used for improving the corrosion resistance of aluminum alloys is chromate (CrVI-based) conversion coatings (CCC). Due to the high environmental impact of these compounds, the REACH Regulation of the European Union decided to limit/restrict the use of hexavalent chromium. A sunset date of mid-2017 has been already set. For the time being, many chromatefree alternative products are available, but they have been found to be significantly inferior in terms of corrosion protection performances with respect to the chromate options. In this regard, there is a great need to develop high-performance hexavalent chromiumfree anticorrosion coatings with low environmental impact and conformity with the EU regulations. The European Space Agency (ESA) is currently involved in a frame contract with Instituto de Soldadura e Qualidade (ISQ) that is currently ongoing. The objective of this study is to evaluate the anticorrosion behavior of the different alternative pretreatments applied to the most used aluminum alloys. The outcome of this activity will be the identification and the optimization of the most promising anticorrosion pretreatment. Several commercial Cr(VI)-free processes were applied onto aluminum alloys (2024-T3 and 2024-T81) used in the construction of ESA spacecraft in order to investigate their anticorrosive properties compared with Alodine 1200, a widely used conventional CCC. One of these commercial processes presented good anticorrosion performance, even better than Alodine 1200, and these results are presented in this paper. Salt spray resistance is included in the testing program as well as metallurgical coating evaluations that include microscopy observations before and after testing and electrochemical impedance spectroscopy in order to evaluate surface and microstructural modifications due to degradation mechanisms. Further studies must be performed with this promising alternative, modifying application parameters in order to achieve improved corrosion protection efficiency.

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Section: Impedance Measurementsmentioning

confidence: 89%

Alternative corrosion protection pretreatments for aluminum alloys

et al. 2017

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“…TiO 2 / CP nanocomposites have been widely investigated be- cause the corrosion resistance was enhanced due to the presence of TiO 2 particles in the coating system. They can form better dispersion for paint formulation which provides barrier properties in the coatings [379][380][381]. Recently, Pagotto et al [382] reported multilayers of PANI/ n-TiO 2 (TiO 2 nanotubes) on carbon steel and welded carbon steel for corrosion protection.…”

Section: Corrosion Protectionmentioning

confidence: 99%

Recent progress on nanostructured conducting polymers and composites: synthesis, application and future aspects

et al. 2018

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“…In addition, aluminum is provided with low price, high electrical capacity and high energy density [1]. The resistance of aluminum against corrosion in aqueous media can be attributed to a rapidly formed surface oxide film [2,3]. However, the presence of aggressive chloride ions creates extensive localized attack, because of the migration of chloride ions through the film.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, the applications of the TiO 2 coatings for corrosion protection of metals have been investigated [19,20], especially because they can prevent migration of chloride into the aluminum film. Based on previous discussions, the aim of this study is to design stable, compact and higher load capacity functional films assisted with efficient combination between pure TiO 2 coatings with anodized Al surfaces by a vacuum dip-coating method.…”

Section: Introductionmentioning

confidence: 99%