Interaction of Chromate Ions with Surface Intermetallics on Aluminum Alloy 2024-T3 in NaCl Solutions

Kolics, A.; Besing, A. S.; Wiȩckowski, Andrzej

doi:10.1149/1.1380674

Cited by 61 publications

(52 citation statements)

References 25 publications

(43 reference statements)

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“…AES studies have shown that a chromium-rich (Cr III -Cr VI ) film forms on the entire surface of AA2024-T3, but preferentially on the Al 2 CuMg inclusions, when chromate is added to the sodium chloride solution. 19,20 It was suggested that chromate strongly inhibits magnesium dissolution and prevents copper redeposition on the bulk matrix, which is in agreement with our data.…”

Section: Resultssupporting

confidence: 92%

A Study of Corrosion and Pitting Initiation of AA2024-T3 Using Atomic Force Microscopy

Leblanc

Frankel

2002

J. Electrochem. Soc.

247

132

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The corrosion behavior of a population of microstructural inclusions in AA2024-T3 and the interactions between individual inclusions were investigated using atomic force microscopy-based techniques. The results showed that Al-Cu-Fe-Mn intermetallic particles were cathodic in nature and interacted strongly with their surroundings. For large exposed areas, it was found that pitting initiated at a few Al 2 CuMg particles, which became active upon film breakdown even though scanning Kelvin probe force microscopy measurements in air showed they were noble with respect to the matrix prior to the exposure. The size and location of the cathodic regions proved to be critical issues. Accelerated matrix dissolution took place for exposed areas containing a large area fraction of AlCu-Fe-Mn inclusions. The location of the cathodic sites had a strong influence on the local chemistry of the environment and controlled the corrosion behavior of the surface. Potentiodynamic measurements made using a remote cathode indicated no copper redeposition around the pit and on the matrix, in contrast with open-circuit exposure, where active cathodic inclusions modify the local pH. It was also found that pits generated at Al 2 CuMg inclusions became ennobled as a result of Cu enrichment but did not become active cathodic sites.Investigations into the corrosion behavior of AA2024-T3 have shown that this aluminum alloy is susceptible to pitting and inter-granular corrosion in sodium chloride environments.

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Section: Resultssupporting

confidence: 92%

A Study of Corrosion and Pitting Initiation of AA2024-T3 Using Atomic Force Microscopy

Leblanc

Frankel

2002

J. Electrochem. Soc.

247

132

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“…The interest in CO adsorption is mainly due to the detrimental role of adsorbed carbon monoxide in electrocatalysis, where it often acts as a poisoning intermediate that blocks active surface sites. This blocking effect, however, can be positive in other cases, for example in corrosion, a field that has also attracted Wieckowski's attention [8][9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Inhibition by CO of the corrosion of Fe, Ni, and their alloys in concentrated HCl solutions

Cabello

Funkhouser

Cassidy

et al. 2011

Journal of Electroanalytical Chemistry

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a b s t r a c tInhibition by CO of the corrosion of Fe, Ni, and three alloys, containing either Fe and large amounts of Ni (Incoloy 825) or large amounts of Fe (Uniloy-420 and N80 steels) in solutions containing between 7.5% and 28% HCl was studied using potentiodynamic polarization curves, gravimetric tests, and FTIRS. In all cases, but Uniloy-420 in 28% HCl, a clear inhibition of corrosion in the presence of CO in the solution was shown by the gravimetric tests and from cyclic voltammetry, the inhibition being higher in the case of Ni and Ni-containing alloys. CO chemisorbed on Fe and/or Ni atoms present on the alloy surface was identified as the species responsible for corrosion inhibition. The inhibition of corrosion is higher in the cases of Ni and Incoloy 825.

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“…Various analytical techniques have been used to study the chemical and structured nature of the CCC formed on Al-Cu alloy, including x-ray photoelectron spectroscopy (XPS), 5,7,25,26 x-ray absorption near-edge structure (XANES) spectroscopy, 10,18 -20,27 secondary ion mass spectrometry (SIMS) 28 and Fourier transform infrared (FTIR) and Raman spectroscopy. 1,24,29 -31 Several studies have shown that the CCC is inhomogenously distributed on the AA2024-T3 surface and that the underlying microstructure induces spatial and depth composition heterogeneity in the CCC.…”

Section: Introductionmentioning

confidence: 99%

On the nature of the chromate conversion coating formed on intermetallic constituents of AA2024‐T3

Vasquez

Halada

Clayton

et al. 2002

Surface & Interface Analysis

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The objective of the research reported in this paper was to refine an existing model for chromate conversion coatings (CCC) formed on the surface of AA2024-T3, an Al-Cu aircraft alloy, by considering the composition and structure of the CCC formed on constituent intermetallic compounds (IMCs). To achieve this aim it was necessary to develop large-area samples composed of compositionally homogeneous thin films of the various IMCs found on the AA2024-T3 surface, which were galvanically attached to thin films of Al-4.2wt.%Cu (representative of the AA2024-T3 matrix). This was performed in a two-step process: disks of IMC compositions were formed by reactive arc melting (RAM), followed by femtosecond laser ablation of the RAM IMCs, resulting in the formation of homogeneous thin films. These thin films were used to analyze the formation of CCC on IMCs, the AA2024-T3 matrix analog and matrix-IMC galvanic couples. Secondary ion mass spectrometry depth profiling revealed significant variations in CCC film thickness and composition related to the underlying IMCs. The SIMS results indicated that the CCC formed on the matrix analog had the same average thickness as the average CCC formed on AA2024-T3, whereas those formed on individual q and S phases were only 9% and 12% as thick, respectively, when uncoupled to the matrix and 11% and 14% as thick when coupled to the matrix. The CCC thickness on the Al 20 Cu 2 (MnFe) 3 was found to be variable, having an islanded structure. Topographical maps indicate that the IMC/matrix boundaries are covered with CCC of a thickness approaching that of the matrix. Inhibition of CCC growth is related to the high copper content (and therefore insufficient aluminum) present in the IMCs compared to the matrix, which provides a more accurate model of CCC formation on AA2024-T3.

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Interaction of Chromate Ions with Surface Intermetallics on Aluminum Alloy 2024-T3 in NaCl Solutions

Cited by 61 publications

References 25 publications

A Study of Corrosion and Pitting Initiation of AA2024-T3 Using Atomic Force Microscopy

A Study of Corrosion and Pitting Initiation of AA2024-T3 Using Atomic Force Microscopy

Inhibition by CO of the corrosion of Fe, Ni, and their alloys in concentrated HCl solutions

On the nature of the chromate conversion coating formed on intermetallic constituents of AA2024‐T3

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