Communication—Role of Trivalent Chromium on the Anti-Corrosion Properties of a TCP Conversion Coating on Aluminum Alloy 2024-T3

2018 ◽  
Vol 165 (2) ◽  
pp. C103-C105 ◽  
Author(s):  
T. K. Shruthi ◽  
Greg M. Swain
Keyword(s):  
Aluminum Alloy ◽  
Trivalent Chromium ◽  
Conversion Coating ◽  
Corrosion Properties ◽  
Aluminum Alloy 2024

Role of Post-Treatment in Improved Corrosion Behavior of Trivalent Chromium Protection (TCP) Coating Deposited on Aluminum Alloy 2024-T3

2017 ◽  
Vol 164 (6) ◽  
pp. C276-C284 ◽  
Author(s):  
Marion Ely ◽  
Jolanta Światowska ◽  
Antoine Seyeux ◽  
Sandrine Zanna ◽  
Philippe Marcus
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Behavior ◽  
Trivalent Chromium ◽  
Post Treatment ◽  
Aluminum Alloy 2024

Role of hydrogen and humidity in the torsional fatigue of aluminum alloy 2024-T351

1985 ◽  
Vol 73 ◽  
pp. 131-138 ◽  
Author(s):  
T.S. Sudarshan ◽  
M.R. Louthan ◽  
T.A. Place ◽  
H.H. Mabie
Keyword(s):  
Aluminum Alloy ◽  
Torsional Fatigue ◽  
Aluminum Alloy 2024

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.

scholarly journals Application of Commercial Surface Pretreatments on the Formation of Cerium Conversion Coating (CeCC) over High-Strength Aluminum Alloys 2024-T3 and 7075-T6

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 930
Author(s):  
Juan Jesús Alba-Galvín ◽  
Leandro González-Rovira ◽  
Francisco Javier Botana ◽  
Maria Lekka ◽  
Francesco Andreatta ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Salt Spray ◽  
Aluminum Matrix ◽  
Optical Emission ◽  
High Strength ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Corrosion Properties ◽  
Surface Pretreatment

The selection of appropriate surface pretreatments is one of the pending issues for the industrial application of cerium-based chemical conversion coatings (CeCC) as an alternative for toxic chromate conversion coating (CrCC). A two-step surface pretreatment based on commercial products has been successfully used here to obtain CeCC on AA2024-T3 and AA7075-T6. Specimens processed for 1 to 15 min in solutions containing CeCl3 and H2O2 have been studied by scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDX), glow discharge optical emission spectroscopy (GDOES), potentiodynamic linear polarization (LP), electrochemical impedance spectroscopy (EIS), and neutral salt spray (NSS) tests. SEM-EDX showed that CeCC was firstly observed as deposits, followed by a general coverage of the surface with the formation of cracks where the coating was getting thicker. GDOES confirmed an increase of the CeCC thickness as the deposition proceed, the formation of CeCC over 7075 being faster than over 2024. There was a Ce-rich layer in both alloys and an aluminum oxide/hydroxide layer on 7075 between the upper Ce-rich layer and the aluminum matrix. According to LP and EIS, CeCC in all samples offered cathodic protection and comparable degradation in chloride-containing media. Finally, the NSS test corroborated the anti-corrosion properties of the CeCC obtained after the commercial pretreatments employed.

The role of brass texture on the deformation response of 7075-T651 aluminum alloy under equi-biaxial tension

2021 ◽  
pp. 141133
Author(s):  
Nedunchezhian Srinivasan ◽  
R. Velmurugan ◽  
Lalith Kumar Bhaskar ◽  
Satish Kumar Singh ◽  
Bhanu Pant ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Biaxial Tension ◽  
Deformation Response
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