scholarly journals Dehydration-Induced Loss of Corrosion Protection Properties in Chromate Conversion Coatings on Aluminum Alloy 2024-T3

2003 ◽  
Vol 150 (9) ◽  
pp. B425 ◽  
Author(s):  
V. Laget ◽  
C. S. Jeffcoate ◽  
H. S. Isaacs ◽  
R. G. Buchheit
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Protection ◽  
Conversion Coatings ◽  
Chromate Conversion Coatings ◽  
Aluminum Alloy 2024

scholarly journals Effects of chromate and chromate conversion coatings on corrosion of aluminum alloy 2024-T3

2001 ◽  
Vol 140 (1) ◽  
pp. 51-57 ◽  
Author(s):  
J. Zhao ◽  
L. Xia ◽  
A. Sehgal ◽  
D. Lu ◽  
R.L. McCreery ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Conversion Coatings ◽  
Chromate Conversion Coatings ◽  
Aluminum Alloy 2024

Chitosan-based self-healing protective coatings doped with cerium nitrate for corrosion protection of aluminum alloy 2024

2012 ◽  
Vol 75 (1-2) ◽  
pp. 8-13 ◽  
Author(s):  
J. Carneiro ◽  
J. Tedim ◽  
S.C.M. Fernandes ◽  
C.S.R. Freire ◽  
A.J.D. Silvestre ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Protection ◽  
Protective Coatings ◽  
Cerium Nitrate ◽  
Self Healing ◽  
Aluminum Alloy 2024

Surface Pretreatments of Aluminum Alloy AA2024-T3 and Formation of Chromate Conversion Coatings

2004 ◽  
Vol 151 (11) ◽  
pp. B613 ◽  
Author(s):  
Devicharan Chidambaram ◽  
Clive R. Clayton ◽  
Martin W. Kendig ◽  
Gary P. Halada
Keyword(s):  
Aluminum Alloy ◽  
Conversion Coatings ◽  
Chromate Conversion Coatings

Performance Comparison of Steam-Based and Chromate Conversion Coatings on Aluminum Alloy 6060

CORROSION ◽  
10.5006/1624 ◽  
2015 ◽  
Vol 71 (7) ◽  
pp. 839-853 ◽  
Author(s):  
Rameez Ud Din ◽  
Morten S. Jellesen ◽  
Rajan Ambat
Keyword(s):  
Aluminum Alloy ◽  
Performance Comparison ◽  
Conversion Coatings ◽  
Chromate Conversion Coatings

Corrosion Protection of Aluminum Alloy 2024-T3 by Vanadate Conversion Coatings

CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 284-296 ◽  
Author(s):  
H. Guan ◽  
R. G. Buchheit
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Protection ◽  
Inductively Coupled Plasma ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Conversion Coating ◽  
Self Healing ◽  
Pitting Potential ◽  
X Ray ◽  
Aluminum Alloy 2024

Abstract In this paper, the formation, chemistry, morphology, and corrosion protection of a new type of inorganic conversion coating is described. This coating, referred to as a vanadate conversion coating (VCC), forms on aluminum alloy substrates in a matter of minutes during simple immersion in aqueous vanadate-based solutions at ambient temperatures. VCCs are yellow in color and conformal across the surface of aluminum alloy 2024-T3 (AA2024-T3 [UNS A92024]) substrates. Auger electron sputter depth profiles and x-ray absorption near-edge spectroscopy show that VCCs formed by a 3-min immersion are 300 nm to 500 nm thick and consist of a mixture of vanadium oxides and other components in the coating bath. In anodic polarization experiments conducted in aerated chloride solutions, VCCs increase the pitting potential and decrease the rate of oxygen reduction. When characterized by electrochemical impedance spectroscopy, VCCs demonstrate a low-frequency impedance between 1 MΩ-cm2 and 2 MΩ-cm2 after 24 h exposure to aerated 0.5 M sodium chloride (NaCl) solutions. In salt spray testing conducted according to ASTM B117, VCCs suppress formation of large pits for more than 168 h. VCCs also appear to be self-healing. Analysis of solution in contact with VCCs by inductively coupled plasma emission spectroscopy indicates that vanadate is released into solution upon exposure. Vanadium deposits were identified by x-ray microchemical analysis on a bare alloy substrate held in close proximity to a vanadate conversion-coated surface, and corrosion resistance of this bare surface was observed to increase during exposure. An important component of VCC formation appears to involve inorganic polymerization of V5+, which leads to the buildup of a film that passivates the surface and inhibits corrosion.

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