Localized attack of a two-phase metal, scanning electrochemical microscopy studies of NiCrMoGd alloys

Lister, Tedd E.; Pinhero, P. J.; Trowbridge, Tammy L.; Mizia, R.E.

doi:10.1016/j.jelechem.2005.02.019

Cited by 15 publications

(6 citation statements)

References 29 publications

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“…Thus, this technique has proven to be a very useful tool for studying a wide range of corrosion processes, including bimetallic corrosion, [1][2][3] dissolution of inclusions in alloys, [4][5][6] controlled generation of single pits in otherwise passive metals, [7][8][9] monitoring of precursor sites for pit nucleation in oxide layers [10][11][12] as well as detection of the metastable pitting regime [13,14] and the onset of corrosion processes from defective coatings. [15][16][17][18] Two recent reviews on further uses of SECM in the field of corrosion can be found in references [19,20].…”

Section: Introductionmentioning

confidence: 99%

Application of AC‐SECM in Corrosion Science: Local Visualisation of Inhibitor Films on Active Metals for Corrosion Protection

Pähler

Santana

Schuhmann

2010

Chemistry A European J

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The suitability of frequency-dependent alternating-current scanning electrochemical microscopy (4D AC-SECM) for investigation of thin passivating layers covering the surface of corrosion-inhibited metals has been demonstrated. Inhibition of copper corrosion by benzotriazole (BTAH) and methylbenzotriazole (MBTAH), which are effective inhibitors for this metal under many environmental conditions, was investigated. Strong dependencies were found for the AC z-approach curves with both the duration of the inhibitor treatment and the frequency of the AC excitation signal applied in AC-SECM. Both negative and positive feedback behaviours were observed in the AC approach curves for untreated copper and for Cu/BTAH and Cu/MBTAH samples. Negative feedback behaviour occurred in the low-frequency range, whereas a positive feedback effect was observed at higher frequencies. A threshold frequency related to the passage from negative to positive regimes could be determined in each case. The threshold frequency for inhibitor-modified samples was found always to be significantly higher than for the untreated metal, because the inhibitor film provides electrical insulation for the surface. Moreover, the threshold frequency increased with increasing surface coverage by the inhibitor. 4D AC-SECM was successfully applied to visualizing spatially resolved differences in local electrochemical activity between inhibitor-free and inhibitor-covered areas of the sample.

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Section: Introductionmentioning

confidence: 99%

Application of AC‐SECM in Corrosion Science: Local Visualisation of Inhibitor Films on Active Metals for Corrosion Protection

Pähler

Santana

Schuhmann

2010

Chemistry A European J

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“…A number of studies about the properties of passive films have been reported for pure titanium, including integral measurements, 18,[22][23][24][25][26][27][28][29] local investigations using scanning electrochemical microscopy ͑SECM͒, [30][31][32][33][34][35] and other scanning probe techniques. 36 Much less is known about the local behavior of the passive layer on biphasic titanium-based alloys and especially on possible differences in the properties of the passive layers on the different phases.…”

mentioning

confidence: 99%

Electron Transfer Kinetics at Oxide Films on Metallic Biomaterials

Pust¹,

Scharnweber²,

Baunack³

et al. 2007

J. Electrochem. Soc.

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A native oxide film on the biphasic alloy Ti6Al4V was studied with scanning electrochemical microscopy (SECM). This alloy is commonly used for biomedical applications due to its biocompatibility and mechanical properties. The heterogeneously composed, n-semiconducting oxide film is of particular interest as biological systems are in contact only with these oxides and immunological rejection mechanisms may be connected to their electrochemical properties. Auger electron spectroscopy showed that the elemental composition of the oxide films on the α and β phase differ from each other. Approach curves were recorded above individual grains of the α phase in the feedback mode with several redox mediators. They were selected to cover a wide range of redox potentials for a better understanding of the surface kinetics of the oxide layer. The electron-transfer kinetics changed strongly depending on the redox potential of the mediator with respect to the energetic position of the bandgap of the oxide film. Predictions about the value of the flatband potential on an individual phase were derived from these experiments. Furthermore, SECM images were recorded to laterally resolve different electrochemical properties of the oxide film originating from the heterogeneous composition of the oxide on both phases.

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“…It complements other scanning probe techniques such as the scanning reference electrode technique (SRET) [178,179], conductive scanning force microcopy (CSFM), electrochemical scanning tunneling microscopy (ECSTM), and scanning Kelvin probe techniques which are popular methods for the investigation of functional materials [180]. Basic experimental approaches include the imaging of the permeability of applied protective coatings [181][182][183][184][185][186][187][188][189][190][191][192][193], the imaging of regions with distinctly higher electron transfer rates which may be precursor sites for pitting corrosion [29,57,[194][195][196][197][198][199][200][201][202][203][204][205][206][207], the initiation of pitting corrosion by local generation of aggressive species at the UME [208,209] and the detection of active corrosion by collecting released species [55,58,60,104,[210][211][212][213][214]…”

Section: Localized Corrosionmentioning

confidence: 99%

“…The active corrosion of a neutron-absorbing NiCrMoGd alloy which is used for nuclear waste storage applications was followed by Lister et al [213] with the I -.I 3 -redox pair in SG.TC mode. I -is oxidized at active regions of the substrate, and I 3 -is then collected at the UME.…”

Section: +mentioning

confidence: 99%

Investigation of Localized Catalytic and Electrocatalytic Processes and Corrosion Reactions with Scanning Electrochemical Microscopy (SECM)

Pust¹,

Maier²,

Wittstock³

2008

Zeitschrift Für Physikalische Chemie

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Scanning Electrochemical Microscopy (SECM) . Catalytic Electrodes .Electrochemical Energy Conversion . Fuel Cells . Oxygen Reduction Reaction . CorrosionScanning electrochemical microscopy (SECM) has developed into a very versatile tool for the investigation of solid-liquid, liquid-liquid and liquid-gas interfaces. The arrangement of an ultramicroelectrode (UME) in close proximity to the interface under study allows the application of a large variety of different experimental schemes. The most important have been named feedback mode, generation-collection mode, redox competition mode and direct mode. Quantitative descriptions are available for the UME signal, depending on different sample properties and experimental variables. Therefore, SECM has been established as an indispensible tool in many areas of fundamental electrochemical research. Currently, it also spreads as an important new method to solve more applied problems, in which inhomogeneous current distributions are typically observed on different length scales. Prominent examples include devices for electrochemical energy conversion such as fuel cells and batteries as well as localized corrosion phenomena. However, the direct local investigation of such systems is often impossible. Instead, suitable reaction schemes, sample environments, model samples and even new operation modes have to be introduced in order to obtain results that are relevant to the practical application. This review outlines and compares the theoretical basis of the different SECM working modes and reviews the application in the area of electrochemical energy conversion and localized

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Localized attack of a two-phase metal, scanning electrochemical microscopy studies of NiCrMoGd alloys

Cited by 15 publications

References 29 publications

Application of AC‐SECM in Corrosion Science: Local Visualisation of Inhibitor Films on Active Metals for Corrosion Protection

Application of AC‐SECM in Corrosion Science: Local Visualisation of Inhibitor Films on Active Metals for Corrosion Protection

Electron Transfer Kinetics at Oxide Films on Metallic Biomaterials

Investigation of Localized Catalytic and Electrocatalytic Processes and Corrosion Reactions with Scanning Electrochemical Microscopy (SECM)

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