Characterisation of surface preparation of 2024 aluminium alloy for conversion coating

Hughés, A.E.; Taylor, Roger; Nelson, K. J.; Hinton, Bruce; Wilson, L.

doi:10.1179/mst.1996.12.11.928

Cited by 31 publications

(22 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Typically, several steps are employed to protect the alloy: surface cleaning and deoxidizing, 1 conversion coating 2,3 or anodizing, 4 organic primer coating and decorative top coating. [5][6][7] Cleaning and deoxidizing remove debris, lubricants, and near-surface deformed layers.…”

mentioning

confidence: 99%

Protective Film Formation on AA2024-T3 Aluminum Alloy by Leaching of Lithium Carbonate from an Organic Coating

Liu

Visser

Zhou

et al. 2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

An investigation into corrosion inhibition properties of a primer coating containing lithium carbonate as corrosion inhibitive pigment for AA2024 aluminum alloy was conducted. It was found that, during neutral salt spray exposure, a protective film of about 0.2 to 1.5 μm thickness formed within the area where an artificial defect was introduced by scribing through the coating to the base alloy. This film showed a multilayered structure consisting of a relatively compact layer near the alloy substrate, a porous middle layer and a columnar outer layer. The thicknesses of the layers varied, as a consequence of the difference in the local concentration of lithium species leaching from the primer coating. The presence of the film in the scribed area significantly reduced corrosion of the alloy, with little consumption of the metal substrate within the scribed area during neutral salt spray exposure. Furthermore, the presence of the protective film resulted in a significant increase of impedance modulus, measured after the salt spray exposure.

show abstract

mentioning

confidence: 99%

Protective Film Formation on AA2024-T3 Aluminum Alloy by Leaching of Lithium Carbonate from an Organic Coating

Liu

Visser

Zhou

et al. 2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…For the coating solutions, titration of acidifi ed cerium chloride/H 2 O 2 solutions shows an initial increase to a buffer region around pH 3, this is followed by a further increase to pH 6 …”

Section: Oxidants: Hydrogen Peroxidementioning

confidence: 98%

“…155,157,161,185 This is because the deoxidizer leaves an extremely thin, passivating oxide containing chromate ions on the surface of the alloy. 6,183,186,187 This oxide must be removed during coating prior to rare earth deposition occurring.…”

Section: Boehmite Formation In Solutions Containing Rare Earthsmentioning

confidence: 99%

“…97 The objective of these cleaning processes is to render the surface in a reproducible state after processing, regardless of the source of material, and there are standard processes for chromate conversion coating or anodizing of aerospace alloys. 6,182,183 The process steps remove surface grease and oils, surface oxides and surface intermetallic particles. In particular they aim to produce a surface with the minimal amount of Cu, although Cu build-up is inevitable even for low-Cu containing alloys.…”

Section: Boehmite Formation In Solutions Containing Rare Earthsmentioning

confidence: 99%

“…Figure 7.1 illustrates the typical process steps for the application of a chromate conversion coating to a high strength aluminium alloy in the aircraft industry. [3][4][5][6] The fl owchart shows a multistep immersion process involving the following steps.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Coatings for corrosion prevention based on rare earths

Hughes

Harvey

Birbilis

et al. 2014

Rare Earth-Based Corrosion Inhibitors

View full text Add to dashboard Cite

Characterization of non‐Cr‐based deoxidizers on Al alloy 7475‐T7651

Toh

Hughés

McCulloch

et al. 2004

Surface & Interface Analysis

View full text Add to dashboard Cite

Al alloy 7475-T7651 were investigated. Several analytical methods were employed, including SEM, AES, transmission electron microscopy (TEM), electron energy-loss spectroscopy (EELS) and glow discharge optical emission spectrometry (GDOES), to study the effects on the surface of this alloy after each treatment compared with the as-received and alkaline-cleaned alloy surfaces. The untreated alloy was found to have a thick oxide of 200-320 nm, consisting mainly of MgO. Alkaline cleaning results in an etching effect that thins the oxide and also deposits a thin silicate layer on the surface. In the case of the deoxidizers, there is significant removal of the native oxide of the alloy by the NaBrO 3 /HNO 3 deoxidizer. There is also evidence of intermetallic attack on the alloy. The (NH 4 ) 4 Ce(SO 4 ) 4 /H 2 SO 4 deoxidizer, which is a low-etch-rate deoxidizer, resulted in a slight thinning of the oxide. However, the effect was not significantly greater than with alkaline cleaning alone. The most effective deoxidizer in reducing the oxide thickness of the alloy is Fe(III)/HF/HNO 3 , in which the etch rate was sufficiently high to remove completely the native oxide. In this case, equilibrium between oxide removal and the formation of new oxides on the alloy surface was achieved.

show abstract

Characterisation of surface preparation of 2024 aluminium alloy for conversion coating

Cited by 31 publications

References 15 publications

Protective Film Formation on AA2024-T3 Aluminum Alloy by Leaching of Lithium Carbonate from an Organic Coating

Protective Film Formation on AA2024-T3 Aluminum Alloy by Leaching of Lithium Carbonate from an Organic Coating

Coatings for corrosion prevention based on rare earths

Characterization of non‐Cr‐based deoxidizers on Al alloy 7475‐T7651

Contact Info

Product

Resources

About