Anion-Exchange Inhibition of Filiform Corrosion on Organic Coated AA2024-T3 Aluminum Alloy by Hydrotalcite-Like Pigments

2003 ◽  
Vol 6 (3) ◽  
pp. B9 ◽  
Author(s):  
Geraint Williams ◽  
H. Neil McMurray
Keyword(s):  
Aluminum Alloy ◽  
Anion Exchange ◽  
Filiform Corrosion

Inhibition of Filiform Corrosion on Organic-Coated Aluminum Alloy by Hydrotalcite-Like Anion-Exchange Pigments

CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 219-228 ◽  
Author(s):  
H. N. McMurray ◽  
G. Williams
Keyword(s):  
Aluminum Alloy ◽  
Anion Exchange ◽  
Polyvinyl Butyral ◽  
Kelvin Probe ◽  
Free Corrosion Potential ◽  
Filiform Corrosion ◽  
Coating Delamination ◽  
Coating Defect ◽  
Aluminum Alloy 2024

Abstract Novel anion-exchange anticorrosion pigments consisting of nitrate-, carbonate-, and chromate-exchanged hydrotalcite (HT) are shown to inhibit the propagation of filiform corrosion (FFC) effectively on organic-coated aluminum alloy 2024-T3 (AA2024-T3 [UNS A92024]) alloy. The HT-pigments are dispersed in polyvinyl butyral (PVB) coatings applied to the AA2024-T3 surface. Following FFC initiation by application of controlled amounts of aqueous hydrochloric acid (HCl) to a penetrative coating defect, the time-dependent extent of coating delamination is determined both optically and by repeated in-situ scanning using a scanning Kelvin probe (SKP) apparatus. All the HT-pigments profoundly reduce rates of coating delamination by comparison to unpigmented samples. However, inhibitor efficiency is dependent upon the exchangeable anion and increases in the order: carbonate < nitrate < chromate. It is also shown that by using SKP potentiometry, exchangeable chromate anions interact specifically with the metal surface to depress free corrosion potential values.

Development of Galvanized Aluminum Alloy Sheet for Body Panels with an Excellent Filiform Corrosion Resistance

1993 ◽  
Author(s):  
Kouichi Kaneko ◽  
Asao Mochizuki ◽  
Hiroki Nakajima ◽  
Kouki Ikeda ◽  
Kikuo Toyose
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Alloy Sheet ◽  
Aluminum Alloy Sheet ◽  
Filiform Corrosion

Effect of Sanding for Aluminum Alloy Sheets on the Filiform Corrosion after Painting

1994 ◽  
Vol 43 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Xulin Sun ◽  
Akira Takahashi ◽  
Yasuhiko Miyoshi
Keyword(s):  
Aluminum Alloy ◽  
Filiform Corrosion

Filiform Corrosion Morphologies on Painted Aluminum Alloy 3105 Coil Material

CORROSION ◽  
1997 ◽  
Vol 53 (9) ◽  
pp. 705-717 ◽  
Author(s):  
H. Leth-Olsen ◽  
K. Nisancioglu
Keyword(s):  
Aluminum Alloy ◽  
Filiform Corrosion

Crosslinked Organic-Inorganic Hybrid Thin Films for Corrosion Resistance: Spectroscopic and Salt Spray Characterization

2000 ◽  
Vol 628 ◽  
Author(s):  
Tammy L. Metrokeand ◽  
Edward T. Knobbe
Keyword(s):  
Thin Films ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Salt Spray ◽  
Crosslinking Agent ◽  
Film Structure ◽  
Organic Polymer ◽  
Paint Systems ◽  
Filiform Corrosion ◽  
Cure Time

ABSTRACTSpray-coated, R-Si (OR')3 / TMOS (R = epoxide), thin films are being investigated as room temperature curing corrosion resistant coatings for 2024-T3 aluminum alloy. Solid state 1H-13C CP/MAS NMR indicates that primary aliphatic amines and super acids are effective crosslinkers for epoxide groups in aqueous ormosil systems. Incorporation of a crosslinking agent into the coating was found to reduce the cure time of the deposited film from >7 days to approximately 30 min. Accelerated salt spray and filiform corrosion resistance tests were conducted to determine the effects of crosslinking on the corrosion resistance behavior of ormosil thin films. The choice of curing agent was found to influence film structure and corrosion resistance properties. Amine cured thin films were hard and highly adherent to the aluminum alloy substrates, exhibiting excellent bare and filiform corrosion resistance, in addition to good compatibility with organic polymer paint systems. In contrast, the adhesion and corrosion resistance of super acid cured thin films to aluminum alloy substrates was significantly less, producing films which readily delaminated from the substrate. These observations can be related to the film structure.

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