The influence of the primer layer on mechanical damage and loss of corrosion protection of deformed painted Zn-0.16% Al and Zn-5% Al galvanized sheet steel

Laverde, Dionisio; Zubillaga, J.C.; Sevillano, J. Gil; Villanueva, Ester

doi:10.1016/0010-938x(94)00116-n

Cited by 17 publications

(3 citation statements)

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“…This model is largely applied even in these days, and describes many corrosion circumstances. [6][7][8] In the last decade, the performance of electronic devices is considerably improved, which allows the measurements of higher and higher impedances. Nowadays, the measured modulus is huge, on the order of teraohms.…”

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confidence: 99%

Electrochemical Impedance Spectroscopy of Epoxy-Vinyl Coating in Aqueous Medium Analyzed by Dipolar Relaxation of Polymer

Duval

Keddam²,

Sfaira

et al. 2002

J. Electrochem. Soc.

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The performance of electrochemical devices, namely, the potentiostat, has increased considerably lately, and some commercial devices determine impedance on the order of teraohms (10 12 ⍀). At the same time, the protective effectiveness of paint films has also improved markedly, and the paint films exhibit capacitance behavior only in the millihertz range. Up to now, electrochemical impedance spectroscopy ͑EIS͒ spectra of polymer-coated specimens were interpreted with a mechanism involving only the film resistance due to flaws through the polymer layer and the film capacitance. However, since almost no flaw should be present at huge impedance, a new insight in the modeling of EIS data for polymer coated metal electrode is needed. Therefore, the concept of dipolar relaxation developed in polymer science is introduced to interpret EIS data. To compare the dipolar relaxation and the electrode impedance, the Cole-Cole capacitance determined straightforwardly from impedance spectra was found to be a very powerful tool. It is shown that the water uptake of a paint film could be evaluated from the Cole-Cole capacitance at infinite frequency C(ϱ), because the plasticizing effect induced by absorbed water in lower frequencies may lead to an overestimation of water uptake.Organic polymer coatings are widely used to reduce the corrosion of metallic structures exposed to aggressive media. Generally, it is considered that the paint film acts as a barrier layer that isolates the substrate metal from aggressive agents. 1,2 Therefore, the water uptake and ion migration inside the coating are determining factors of protective performance. [3][4][5] Electrochemical impedance spectroscopy ͑EIS͒ constitutes a powerful tool to evaluate these parameters. The EIS technique was applied for the first time in the early 1970s to the corrosion study for evaluating the protective effectiveness of paint film. 3 In early work, the measured impedance was low, and the resistance of organic coating was associated with the ionic conductance of electrolyte due to coating film breakdown, such as pores or crevasses. Electrolyte is then directly in contact with substrate metal, and the corrosion process takes place at delaminated areas of coating. This model is largely applied even in these days, and describes many corrosion circumstances. 6-8 In the last decade, the performance of electronic devices is considerably improved, which allows the measurements of higher and higher impedances. Nowadays, the measured modulus is huge, on the order of teraohms. 9 EIS becomes then sensitive to the intrinsic film conductance, due to ionic impurities in the film. The mobility of macromolecular chains and that of ions inside polymer layer becomes the determining factor of the film properties. Consequently, it becomes necessary to associate the EIS spectra to the relaxation of organic macromolecules and intrinsic ionic conduction. 10 A coating of epoxy-vinyl paint often protects pumping stations and tubing with mild steel structures in agricultural irrigation system...

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confidence: 99%

Electrochemical Impedance Spectroscopy of Epoxy-Vinyl Coating in Aqueous Medium Analyzed by Dipolar Relaxation of Polymer

Duval

Keddam²,

Sfaira

et al. 2002

J. Electrochem. Soc.

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“…Particularly, Al added into zinc bath gives rise to the formation of the Zn-Al alloy coating. Specifically, hot-dip 5Al-Zn alloy coating was prepared in 1960s, which is intensively applied to car now, while hot-dip 55Al-Zn alloy coating with a small amount of Si is used in unpainted roof and car parts [4,5,6,7]. A new hot dip 7wt.％Al-Zn alloy coating is utilized to prevent from corrosion in coastal area [9].…”

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confidence: 99%

Structure and Performances of 7075 Aluminum Alloy Surface Subject to Hot-Dip Zinc

Qiao

Yang

et al. 2017

KEM

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The hot-dip galvanized coating was produced on the 7075 aluminum alloy plate by immersion in a pure zinc bath at different temperature from 440°C to 470°C for different modification time (between 1 min and 10 min). The hot-dip galvanized of the treated and un-treated samples were investigated by using scanning electron microscopy (SEM) with EDX analysis, X-ray diffraction (XRD), hardness measurements and potentiodynamic polarization curves. There were three layers fabricated on the 7075 substrate surface, specifically, zinc-rich layer, two-phase mixed layer Al-Zn and interdiffusion layer. Moreover, the 7075 aluminum alloy with the hot-dip galvanized coating exhibit higher hardness and better anti-corrosion properties in comparison with the 7075 substrate.

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“…Aluminum-zinc alloys are widely used as protective coating and structural material in the fields of aviation, automobile, rail transit, ship and electronics for their good mechanical properties and excellent corrosion resistance. [1][2][3][4][5] The production of Al-Zn alloy is mainly using the hot-dip process. However, this process forms intermetallic compounds and the oxides on the substrate due to high temperature operation, which reduces corrosion resistance and the adhesion of coatings.…”

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confidence: 99%

Eco-Friendly Electrodeposition of Al-Zn Alloy from AlCl₃-Urea Deep Eutectic Solvent

Chen,

Xu,

et al. 2024

J. Electrochem. Soc.

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The electrodeposition of Al-Zn alloy from an aluminium chloride-urea (AlCl3-urea) deep eutectic solvent (DES) containing 0.1 M ZnCl2 near room temperature was investigated. Cyclic voltammetry demonstrates that Al and Zn can be co-deposited, but the presence of Zn(II) restrains the reduction of Al(III). Linear sweep voltammetry reveals that increasing temperature facilitates the reduction of Zn(II) and Al(III), but the promotion effect on the Zn(II) reduction is greater than that on Al(III) reduction. Chronoamperometry analysis indicates that the electrocrystallization of Al-Zn alloy on a glassy carbon electrode follows instantaneous nucleation, which is similar to that of pure Al. Scanning electron microscopy shows that the obtained alloy coating is smooth but not compact. With the increase of temperature, the content of Zn in deposits increases, the grain grows up and the microstructure transforms from granular to cluster structure. Energy-dispersive spectroscopy and X-ray diffraction analysis prove that the deposits are pure Al-Zn alloy and composed of α phase and η phase. Tafel polarization test confirms the as-prepared alloy coating with higher Zn content (45 wt.%) possesses excellent corrosion resistance. All these findings promise an eco-friendly and simple route to produce the Al-Zn alloy coating with excellent corrosion resistance near room temperature.

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The influence of the primer layer on mechanical damage and loss of corrosion protection of deformed painted Zn-0.16% Al and Zn-5% Al galvanized sheet steel

Cited by 17 publications

References 1 publication

Electrochemical Impedance Spectroscopy of Epoxy-Vinyl Coating in Aqueous Medium Analyzed by Dipolar Relaxation of Polymer

Electrochemical Impedance Spectroscopy of Epoxy-Vinyl Coating in Aqueous Medium Analyzed by Dipolar Relaxation of Polymer

Structure and Performances of 7075 Aluminum Alloy Surface Subject to Hot-Dip Zinc

Eco-Friendly Electrodeposition of Al-Zn Alloy from AlCl₃-Urea Deep Eutectic Solvent

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The influence of the primer layer on mechanical damage and loss of corrosion protection of deformed painted Zn-0.16% Al and Zn-5% Al galvanized sheet steel

Cited by 17 publications

References 1 publication

Electrochemical Impedance Spectroscopy of Epoxy-Vinyl Coating in Aqueous Medium Analyzed by Dipolar Relaxation of Polymer

Electrochemical Impedance Spectroscopy of Epoxy-Vinyl Coating in Aqueous Medium Analyzed by Dipolar Relaxation of Polymer

Structure and Performances of 7075 Aluminum Alloy Surface Subject to Hot-Dip Zinc

Eco-Friendly Electrodeposition of Al-Zn Alloy from AlCl3-Urea Deep Eutectic Solvent

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Product

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Eco-Friendly Electrodeposition of Al-Zn Alloy from AlCl₃-Urea Deep Eutectic Solvent