Investigation of the corrosion behaviour of a bilayer cerium-silane pre-treatment on Al 2024-T3 in 0.1M NaCl

Palomino, Luis; Suegama, P. H.; Aoki, Idalina Vieira; Pászti, Zoltán; Melo, Hercílio Gomes de

doi:10.1016/j.electacta.2007.03.002

Cited by 78 publications

(62 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, the morphological analysis reveals the existence of microcracks systems for the T0, T1 and T2 samples, due to the fragility of thicker layers, and hence a decrease in corrosion resistance can be seen. Additionally, it is generally accepted that the cracked microstructure of the largest number of layers hybrid films is due to the drying stage 28 , because of the introduction of compressive stress during the cross-linking of the silane layer in the curing step 29 . Figure 6 displays the AFM 3-D images of the studied systems from a 70 × 70 µm 2 area whereas the roughness values are summarized in Table 2.…”

Section: Structural Featuresmentioning

confidence: 99%

Effect of Tetraethoxy-silane (TEOS) Amounts on the Corrosion Prevention Properties of Siloxane-PMMA Hybrid Coatings on Galvanized Steel Substrates

et al. 2015

View full text Add to dashboard Cite

Siloxane-poly(methyl methacrylate) (PMMA) organic-inorganic hybrid coatings were deposited on galvanized steel by the dip-coating sol-gel technique. Anticorrosion properties, as well as the morphological, surface and structural features were studied. Hybrid coatings were synthesized from tetraethoxy-silane (TEOS) and methyl methacrylate (MMA) as inorganic and organic phases, respectively, linked by 3-metacriloxypropyl-trimethoxysilane (TMSM) as a coupling agent. The MMA/TMSM ratio was kept constant, whereas the four TEOS/TMSM ratios were varied. The characterization of coatings was assessed using several techniques such as Scanning Electronic Microscopy (SEM), Contact Angle, Fourier Transform Infrared (FT-IR), Open Circuit Polarization (OCP), Atomic Force Microscopy (AFM) and Electrochemical Impedance Spectroscopy measurements (EIS). The EIS results, which were obtained for the hybrid coatings, were discussed based on an electrical equivalent circuit used to adjust the experimental data. The results showed that the increasing the TEOS content caused increase in coating thickness, increased in the surface roughness and increased in the surface hydrophobicity. The film with the highest TEOS content presented the best electrochemical performance, more effective in protecting against corrosion.

show abstract

Section: Structural Featuresmentioning

confidence: 99%

Effect of Tetraethoxy-silane (TEOS) Amounts on the Corrosion Prevention Properties of Siloxane-PMMA Hybrid Coatings on Galvanized Steel Substrates

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Figure 1 presents micrographs of the bare sample, Figure 1a, and of the AA 2024-T3 alloy coated with the different treatments: Ce conversion layer (Figure 1b), silane film ( Figure 1c) and bi-layer Ce-silane (Figure 1d). These images have already been discussed elsewhere 39 , however their main aspects will be highlighted. The bare sample presents coarse Al-Cu-Mg and Al-Cu-Fe-Mn intermetallics distributed on its whole surface, while, the Ce coated sample presents its usual dry-mud appearance.…”

Section: Methodsmentioning

confidence: 99%

Comparative investigation of the adhesion of Ce conversion layers and silane layers to a AA 2024-T3 substrate through mechanical and electrochemical tests

Palomino¹,

Pászti²,

Aoki³

et al. 2007

Mat. Res.

Self Cite

View full text Add to dashboard Cite

Cerium conversion layers and silane films are among the potential substitutes for the carcinogenic chromate conversion layers used to protect high-strength Al alloys. In the present work the adhesion of a cerium conversion layer and of a silane film to an aluminium alloy (AA) 2024-T3 substrate was investigated using mechanical and electrochemical tests. Scanning electron microscopy (SEM)-X ray energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR) and X ray photoelectron spectroscopy (XPS) were used to characterize the layers prior and after the mechanical test consisting of ultrasonic rinse in deionized water during 30 minutes. Mechanically tested and untested layers were also submitted to electrochemical impedance spectroscopy (EIS) and anodic polarization measurements in 0.1 M NaCl solution. The results of the characterization tests have pointed to a stronger adhesion of the Ce layer to the substrate in comparison with the silane film, which was confirmed by the electrochemical tests. The adhesion between the silane film and the Ce conversion layer was also tested, to evaluate the possibility of using the system as a protective bi-layer in accordance with the new trends being developed to substitute chromate conversion layers.

show abstract

“…However, the morphological analysis shows microcracks for the films exposed to high curing temperature, due to the fragile state of thicker layers, and a consequent decrease in corrosion resistance. Additionally, it is generally accepted that the cracked microstructure of the bilayered hybrid films is due to the drying stage 23 , because of the application of compressive stress during the crosslinking of the silane layer in the curing step 24 . The layer thicknesses of the films determined by the analisys of cross section images obtained through SEM (Figure 3), as well as the results are shown in Table 2.…”

Section: Morphological Characterizationmentioning

confidence: 99%

Effect of curing temperature and architectural (monolayer and bilayer) of hybrid films modified with polyethylene glycol for the corrosion protection on tinplate

et al. 2014

View full text Add to dashboard Cite

Hybrid films obtained by a sol-gel process are based on two important reactions: hydrolysis and condensation. The condensation reaction is influenced by the curing temperature, since it induces the development of the intrinsic properties of the gel. The aim of this work is to coat tinplate, a substrate widely used in the packaging industry, with monolayered and bilayered hybrid films modified with polyethylene glycol and obtained through dip-coating. The results showed that the bilayered hybrid film obtained at 60°C had a higher layer thickness, and the best performance in the electrochemical assays, as well as the most hydrophobic character, in relation to the other samples. For the monolayered systems, the 90°C-cured system showed a lower layer thickness; however, this system showed a more compact, uniform and less porous layer, and presented better electrochemical impedance results, in comparison with the 60°C-cured samples.

show abstract

Investigation of the corrosion behaviour of a bilayer cerium-silane pre-treatment on Al 2024-T3 in 0.1M NaCl

Cited by 78 publications

References 39 publications

Effect of Tetraethoxy-silane (TEOS) Amounts on the Corrosion Prevention Properties of Siloxane-PMMA Hybrid Coatings on Galvanized Steel Substrates

Effect of Tetraethoxy-silane (TEOS) Amounts on the Corrosion Prevention Properties of Siloxane-PMMA Hybrid Coatings on Galvanized Steel Substrates

Comparative investigation of the adhesion of Ce conversion layers and silane layers to a AA 2024-T3 substrate through mechanical and electrochemical tests

Effect of curing temperature and architectural (monolayer and bilayer) of hybrid films modified with polyethylene glycol for the corrosion protection on tinplate

Contact Info

Product

Resources

About