An Electrochemical and X‐Ray Photoelectron Spectroscopy Study of the Passive State of Chromium

Moffat, Thomas P.; Latanision, R. M.

doi:10.1149/1.2069514

Cited by 155 publications

(78 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For comparison, the coatings deposited from aqueous electrolytes are covered with a thick (about 20 nm) passive film consisting of chromium oxides and impurities of organic substances [27][28][29]. Although the positions of Cr2p3 peak corresponding to the metallic (BE = 574.5-575.2 eV) and oxide (BE = 576.5-577.9 eV) forms of chromium differ considerably (about 3 eV), the Cr2p3 peak is barely sensitive to the interaction of organic substances with Cr atoms [30,31]. In contrast, the C1s spectra are the most informative ones to determine the nature of organic substances which may be both adsorbed on the surface and in the bulk of the deposit.…”

Section: Resultsmentioning

confidence: 99%

Chromium electrodeposition from [BMIm][BF4] ionic liquid

Surviliene¹,

Eugénio

Vilar

2010

J Appl Electrochem

View full text Add to dashboard Cite

The electrodeposition of black chromium coatings from ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate with chromium chloride, and the chemical composition of the deposits are discussed in this article. The UV-Vis spectra recorded for chromium(III) species in 1-butyl-3-methylimidazolium tetrafluoroborate suggest that along with the chromium(III) complexes containing three ligands, there are some amounts of chromium species containing four ligands in the bath employed. The cathodic process of chromium electrodeposition in the employed ionic liquid is complicated by the electrochemical reduction of water molecules, which is followed by chemical disintegration of tetrafluoroborate ions. The surface morphology of black chromium films deposited potentiostatically (-1.5 to -2.0 V) at 85°C shows nodules and microcracks increasing in size with cathodic potential. Analysis of the X-ray photoelectron spectra recorded from surface to depth of the deposit has shown that the black oxide-rich chromium coating consists of chromium in both oxide and metallic states with small impurities of other elements (fluorine, boron, carbon and nitrogen) and the surface is covered with a thin layer of organic substances. The results of this study show that 1-butyl-3-methylimidazolium tetrafluoroborate may be considered as a promising substitute of toxic Cr(VI) baths for black chromium plating.

show abstract

Section: Resultsmentioning

confidence: 99%

Chromium electrodeposition from [BMIm][BF4] ionic liquid

Surviliene¹,

Eugénio

Vilar

2010

J Appl Electrochem

View full text Add to dashboard Cite

show abstract

“…The polarization behaviour of pure Cr coating in the solution studied was discussed elsewhere [14,15]. The passive film formed on the Cr surface upon anodic oxidation in H 2 SO 4 solution was identified in [16][17][18]. According to [17] the passive film is a thin hydrated chromic oxide (5-25 Å ) that may be considered as a dielectric with a dielectric constant of 25.…”

Section: Resultsmentioning

confidence: 99%

“…The passive film formed on the Cr surface upon anodic oxidation in H 2 SO 4 solution was identified in [16][17][18]. According to [17] the passive film is a thin hydrated chromic oxide (5-25 Å ) that may be considered as a dielectric with a dielectric constant of 25. The decrease in current density in the potential region )0.3 to )0.2 V suggests the formation of Cr(II) oxide or hydroxide.…”

Section: Resultsmentioning

confidence: 99%

“…Figure 3 shows the XPS spectra for Cr2p 3/2 recorded on the outer layers of Cr deposited in baths without WC (curve 1) and with WC (curves 2-4). Two Cr2p 3/2 peaks that can be attributed to Cr 0 metallic and to Cr 2 O 3 , CrOOH and Cr(OH) 3 [16,17] emerged in the XPS spectra. It is seen that the peak positions for both Cr 0 and Cr(III) practically coincide in all samples.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Effect of WC on electrodeposition and corrosion behaviour of chromium coatings

Surviliene¹,

Jasulaitienė²,

Lisowska-Oleksiak

et al. 2005

J Appl Electrochem

View full text Add to dashboard Cite

To study the effect of WC particles on corrosion behaviour of chromium coating steel samples were plated in Cr(VI) baths with various concentrations of WC. XPS, EPM and XRD were used to study the chemical composition, morphology and texture of the coatings. The corrosion behaviour was studied at different exposure times in solution containing 0.01 mol L )1 H 2 SO 4 + 0.5 mol L )1 Na 2 SO 4 using cyclic voltammetry and impedance spectroscopy. Cyclic polarization measurements suggest that WC particles slow down the processes of passive film dissolution and penetration of aggressive ions to the substrate. Electrochemical impedance spectroscopy (EIS) was used to reveal the details of the corrosion process at the solution/electrode interface. The simulation of EIS data with a proposed equivalent circuit model made it possible to obtain quantitative valuation of the Y 0 (Q c ), Y 0 (Q s ) and R pore parameters, reflecting corrosion behaviour of samples at the solution/electrode interface. Samples plated in a Cr(VI) bath with WC provided better resistance to corrosion than those plated in a bath without WC. Analysis of the data obtained suggests that WC particles enhance corrosion resistance due to the microstructural features of the coatings.

show abstract

“…Also, when molybdate ion was added to :he test solution, the corrosion potential (ER) increased and the ic decreased, but the pitting corrosion was observed to propagate rapidly. The cathodic current loop, visible at the base of the passive domain, is attributed to proton reduction on the passive electrode [27]. Therefore, the effect of alloyed molybdenum on the anodic polarization is relatively more potent than that of molybdate addition to the test solution.…”

Section: Effect Of Alloyed Molybdenum and Molybdate Addition On The Cmentioning

confidence: 99%

Influences of alloyed molybdenum and molybdate addition on the corrosion properties and passive film composition of stainless steels

Kim

1998

Metals and Materials

View full text Add to dashboard Cite

The influences of alloyed molybdenum and molybdate addition on the corrosive properties and passive film composition of stainless steels were evaluated. Anodic polarization measurement, solution analysis, and surface analysis were conducted to investigate the influences. The roles of alloyed molybdenum and molybdate addition were observed to vary with the environment. In addition, the role of molybdate addition depended on the presence of nitrogen in the alloy. The composition of the passive film formed by alloyed molybdenum was found to be different from that of the film formed by molybdate addition. These observations suggest that when the thermodynamical condition in the film is suitable for the formation of molybdate, it first forms in the film and then later partially dissolves into a solution and partially evaporates.

show abstract

An Electrochemical and X‐Ray Photoelectron Spectroscopy Study of the Passive State of Chromium

Cited by 155 publications

References 37 publications

Chromium electrodeposition from [BMIm][BF4] ionic liquid

Chromium electrodeposition from [BMIm][BF4] ionic liquid

Effect of WC on electrodeposition and corrosion behaviour of chromium coatings

Influences of alloyed molybdenum and molybdate addition on the corrosion properties and passive film composition of stainless steels

Contact Info

Product

Resources

About