Effect of thickness and sealing treatments on the corrosion protection properties of anodic oxide coatings on AA5005

Fedel, Michele; Franch, Janis; Rossi, Stefano

doi:10.1016/j.surfcoat.2020.126761

Cited by 27 publications

(9 citation statements)

References 44 publications

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“…In this model, R s represents the solution resistance, R b and CPE b represent respectively the resistance and the constant phase element related to the native barrier of the oxide and/or to the corrosion process occurring at the metal/ solution interface. 1 The equivalent circuit illustrated in Fig. 5b has been successfully used for fitting the EIS spectra of the anodized and sealed specimens.…”

Section: Resultsmentioning

confidence: 99%

“…The barrier properties of aluminum anodic oxide films have been widely studied under immersion [5][6][7][8][9] and various salts spray testing. 1,[10][11][12][13] Although most corrosion testing methods are common to several metallic materials, some of them and the testing solutions are usually specific to a given material and a given form of corrosion. Corrosion experts use accelerated corrosion tests in their laboratories to greatly reduce the time required to assess the corrosion protection properties.…”

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confidence: 99%

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The Effect of Spray Testing Condition on the Corrosion Performance of Hydrothermally Sealed Anodic Oxide on a 5005 Aluminum Alloy: Comparison between Neutral Salt Spray, Acetic Salt Spray and Prohesion Testing Methods

Ramdé,

Fedel,

Rossi

2024

J. Electrochem. Soc.

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In this work, the output of different accelerated tests on anodic aluminum oxide (AAO) coatings developed on AA5005 aluminum alloy (sulfuric acid bath and hydrothermal sealing) has been investigated. In particular, three corrosion testing methods, namely neutral salt spray test (NSS), acetic acid salt spray (AASS) and prohesion test, have been performed on the sealed AAO-coated panels in order to investigate the reliability of the obtained results to the electrochemical impedance ones. NSS and prohesion testing results are found to align with findings from electrochemical impedance spectroscopy (EIS). The acetic salt spray test proved highly corrosive, causing rapid depletion of the oxide layer's protective capabilities, as indicated by the EIS analysis. These results seem to be underestimated by optical image analysis.

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Section: Resultsmentioning

confidence: 99%

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confidence: 99%

The Effect of Spray Testing Condition on the Corrosion Performance of Hydrothermally Sealed Anodic Oxide on a 5005 Aluminum Alloy: Comparison between Neutral Salt Spray, Acetic Salt Spray and Prohesion Testing Methods

Ramdé,

Fedel,

Rossi

2024

J. Electrochem. Soc.

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“…Architectural anodization is an electrochemical process in which an aluminum alloy is anodically polarized in a diluted sulfuric acid-based solution (at temperatures close to 20 • C) to produce a protective oxide layer much thicker than the natural oxide film that forms on these types of alloys. Atmospheric corrosion studies carried out in a wide variety of atmospheres have confirmed the superior ability of these types of anodic oxide coatings to protect aluminum against corrosion in aggressive environments, such as marine and heavily polluted atmospheres, provided that a certain critical thickness is exceeded and an appropriate fabrication procedure is used [2][3][4]11]. According to these studies and some surveys performed in buildings, in urban atmospheres that are usually of moderate corrosivity, a durability of about 100 years [12][13][14] can be predicted for anodic coatings, considering the thicknesses usually applied in architecture.…”

Section: Introductionmentioning

confidence: 99%

“…Anodic coatings of lower thicknesses will develop corrosion earlier and can develop pitting corrosion in pure marine atmospheres with high salinity levels, but these processes will require much longer exposure times to occur than in the case of bare aluminum. Increase in the thickness of the anodic coating will delay the initiation of the corrosion process and its extension [2][3][4][5]11].…”

Section: Introductionmentioning

confidence: 99%

Influence of Exposure Conditions and Particulate Deposition on Anodized Aluminum Corrosion

Fontinha

Eustáquio

2022

CMD

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Anodizing is commonly used for corrosion protection of aluminum and its alloys in the construction industry. The anodic aluminum oxide (AAO) coating has a high ability to prevent the development of extensive pitting corrosion in aluminum substrates, particularly in marine sites, as was observed during a 10-year atmospheric corrosion study carried out in several marine and industrial sites. However, this study also evidenced that this coating can be highly affected by the deposition of particulate material in industrial polluted environments, sometimes in unexpected ways. This study presents information on the atmospheric corrosion of anodized aluminum exposed at two different chemical industrial complexes: a fertilizer production plant and a pulp and paper mill. Visual assessment of surface changes, pitting depth and mass variation with exposure were determined to quantify the degradation suffered. Additionally, SEM/EDS analyses were carried out on the exposed surfaces. Based on the results obtained, the role played by the deposition of airborne particles present in the two environments with respect to the type and level of damage observed is discussed. Deposits of roasted pyrite ash and phosphates or of wood chips and lime particles enhanced pitting corrosion or caused dissolution of the AAO coating.

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“…To improve the corrosion resistance of FSW joints, anodic oxide film sealing is considered a significant and necessary way [20,21]. Therefore, hot water sealing (HWS) and potassium dichromate sealing (PDS) are two commonly used and effective sealing methods [22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Fluorinated Siloxane Modified Layered Double Hydroxide Sealing Film to Enhance the Corrosion Resistance of Anodic Oxide Film of Fricition Stir Welding Joint of Aluminum Alloys

Wang

Yang

et al. 2022

Materials

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Aluminum alloys and their welding structures have been widely used in aviation, aerospace, automobiles, ships, and other industrial fields. The non-uniform nature of welding structures of aluminum alloys causes intractable corrosion problems. Anodizing and subsequent sealing processes are common and effective methods to improve the corrosion resistance of welding structures. However, traditional sealing processes like hot water sealing and potassium dichromate sealing are criticized due to energy consumption or toxicity. In this work, a layered double hydroxide (LDH) sealing process with subsequent fluorinated siloxane modification is proposed to improve the corrosion resistance of the anodic oxide film of friction stir welding joints of typical aluminum alloys. The obtained sealing film with typical lamelliform structures of LDH grows well at the defects of oxidation film and also smoothens the sample surface. The hydrophobicity of the film can separate the corrosive medium from the sample surface and further enhance corrosion resistance. As a result, the corrosion current of the welded sample in 3.5 wt.% NaCl solution plummets about 3~4 orders of magnitude compared to the initial state without anodizing, indicating superior corrosion resistance brought by this method.

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Effect of thickness and sealing treatments on the corrosion protection properties of anodic oxide coatings on AA5005

Cited by 27 publications

References 44 publications

The Effect of Spray Testing Condition on the Corrosion Performance of Hydrothermally Sealed Anodic Oxide on a 5005 Aluminum Alloy: Comparison between Neutral Salt Spray, Acetic Salt Spray and Prohesion Testing Methods

The Effect of Spray Testing Condition on the Corrosion Performance of Hydrothermally Sealed Anodic Oxide on a 5005 Aluminum Alloy: Comparison between Neutral Salt Spray, Acetic Salt Spray and Prohesion Testing Methods

Influence of Exposure Conditions and Particulate Deposition on Anodized Aluminum Corrosion

Fluorinated Siloxane Modified Layered Double Hydroxide Sealing Film to Enhance the Corrosion Resistance of Anodic Oxide Film of Fricition Stir Welding Joint of Aluminum Alloys

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