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Akiyama, Tomohiro; Kobayashi, Shígeo; Ki, Joon Seo; Ohgai, Takeshi; Fukushima, Hisaaki

doi:10.1023/a:1004093531922

Cited by 38 publications

(25 citation statements)

References 10 publications

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“…It was confirmed that addition of PEG inhibits the Zn reaction and increases the proximity of the deposition potentials of Zn and Cr [11]. Co-deposition is established at a potential of about -1.95 V (vs. Hg/Hg 2 SO 4 ), which is achieved under galvanostatic conditions at about 20 A dm -2 .…”

Section: Introductionmentioning

confidence: 76%

Deposition of Zn–Cr alloy coatings from sulfate electrolyte: effect of polypropylene glycol 620 and glycine and combinations thereof

et al. 2008

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The effect of polypropylene glycol with molecular mass 620 (PPG 620) and glycine as additives in electrodeposition of Zn-Cr alloy coatings from acidic sulfate electrolyte containing (NH 4 ) 2 SO 4 and H 3 BO 3 , at ambient temperature, without agitation is investigated. PPG 620 inhibits the Zn reaction causing significant proximity of the deposition potentials of Zn and Cr, and a co-deposition at a less negative potential of -1.8 V (vs. Hg/Hg 2 SO 4 ) as compared to the case when polyethylene glycol 1500 (PEG 1500) is used. Depending on the deposition conditions, alloy coatings containing up to 23 mass % Cr can be obtained. Glycine itself does not facilitate the co-deposition of Cr and Zn. Added to the electrolyte containing PPG 620, glycine causes a decrease of the Cr content in the alloy. However, the alloy coatings deposited in the presence of both additives are denser, have better overall appearance and good adherence to the steel substrate. Moreover, glycine increases the buffer capacity of the electrolyte. At short deposition times, the alloy coatings consist mainly of bcc C x -(Zn, Cr) phase with lattice parameter about 3.035 (3) Å and mean crystallite size of the order of 25 nm. Cr content in the coatings can be controlled by changing the concentration of Cr(III) and pH of the electrolyte as well as the current density. Depending on the working conditions, the cathode current efficiency is within 35-55%.

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Section: Introductionmentioning

confidence: 76%

Deposition of Zn–Cr alloy coatings from sulfate electrolyte: effect of polypropylene glycol 620 and glycine and combinations thereof

et al. 2008

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“…Steel sheets with protective Zn coatings are widely used in automotive body panels, electric appliances [4,5], and building materials [6]. During manufacture, Zn coatings are deposited by use of a variety of methods, for example physical vapour deposition, pack cementation [3], hot dip galvanizing (HDG), and electrodeposition or electrogalvanizing (EG).…”

Section: Introductionmentioning

confidence: 99%

“…Typically, formation of these phases depends on deposition conditions, for example mass content of the alloying element [7,8] and the temperature and pH of the depositing electrolyte [6]. Electrodeposition of Zn-Cr alloy coatings is favoured because of their reported excellent properties for applications in the automotive industry and the good steel corrosion protection potential [3,4]-the high corrosionprotection performance of such layers at low coating weight fits well into the "factor four concept: doubling wealth, halving resource use" introduced by Ernest Ulrich von Weizsaecker [9]. Especially, Zn-Cr coatings with a Cr content of 3% to 7% have several advantages, and the mechanical and chemical properties can be easily tuned to the needs of industry, for example, spot and laser weldability or adhesive bondability, compared with HDG-deposited coatings [10].…”

Section: Introductionmentioning

confidence: 99%

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X-ray photoelectron and scanning Auger electron spectroscopy study of electrodeposited ZnCr coatings on steel

et al. 2012

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Zn-Cr alloyed coatings electrochemically deposited are of high interest for leading steel manufacturing companies because of their novel properties and high corrosion resistance compared with conventional Zn coatings on steel. For tuning and optimizing the properties of the electrodeposited Zn-Cr coatings, a broad range of the deposition conditions must be studied. For this reason, two different types of material were investigated in this study, one with a low electrolyte temperature and one with an elevated electrolyte pH, compared with the standard values. Because different corrosion performance and delamination behaviour of the layers were observed for the two types, advanced surface analysis was conducted to understand the origin of this behaviour and to discover differences in the formation of the coatings. The topmost surface, the shallow subsurface region, and the whole bulk down to the coating-steel interface surface were analysed in detail by X-ray photoelectron spectroscopy (XPS) and high-resolution scanning Auger electron spectroscopy to determine the elemental and the chemical composition. For better understanding of the resulting layer structure, multiple reference samples and materials were measured and their Auger and XPS spectra were fitted to the experimental data. The results showed that one coating type is composed of metallic Zn and Cr, with oxide residing only on the surface and interface, whereas the other type contains significant amounts of Zn and Cr oxides throughout the whole coating thickness.

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“…In addition, various studies suggested that PEG adsorbed on an electrode surface forms a barrier that inhibits metal deposition and increases the overpotential for the discharge of the metal ion, for example, Zn(II) 19 or Cu(II) 20 and that the degree of inhibition increases with the increasing molecular weight of the polyethoxylated compound.…”

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confidence: 99%

Thermodynamic Studies of PEG (Mw 20,000) Adsorption onto a Polycrystalline Gold Electrode

Méndez‐Albores

Moroń

Ortiz‐Frade

et al. 2011

J. Electrochem. Soc.

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Cyclic voltammetry, differential capacity, and chronocoulometry were employed in a quantitative study of polyethylene glycol (Mw 20000) (PEG 20000 ) adsorption onto a polycrystalline Au substrate. The surface tension, film pressure, relative Gibbs surface excess, and the Gibbs energy of adsorption were determined as a function of the electrode potential. The results indicated that, in the potential interval studied (À0.9 to 0.35 V vs saturated calomel electrode), PEG 20000 adsorbed onto the polycrystalline Au surface via its oxygen atoms as a flat submonolayer of rodlike molecules. The adsorbed mass increased considerably with the increasing PEG 20000 concentration and more positive potential. In addition, the surface tension decreased as the quantity of PEG 20000 adsorbed on the surface rose with the increasing PEG 20000 concentration, an effect characteristic of surface active agents. The maximum surface concentration was found to be 4.59 Â 10 À10 mol oxygen cm À2 for the highest PEG 20000 concentration studied (100 lM). The Gibbs energy of adsorption (DG ads ) was determined using the Henry adsorption isotherm. On the basis of the DG ads values obtained, it was concluded that the PEG 20000 molecules were weakly chemisorbed on the polycrystalline Au surface.

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Cited by 38 publications

References 10 publications

Deposition of Zn–Cr alloy coatings from sulfate electrolyte: effect of polypropylene glycol 620 and glycine and combinations thereof

Deposition of Zn–Cr alloy coatings from sulfate electrolyte: effect of polypropylene glycol 620 and glycine and combinations thereof

X-ray photoelectron and scanning Auger electron spectroscopy study of electrodeposited ZnCr coatings on steel

Thermodynamic Studies of PEG (Mw 20,000) Adsorption onto a Polycrystalline Gold Electrode

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