Repassivation and pitting of freshly generated aluminium surfaces in acidic nitrate solution

Burstein, G.T.; Organ, R. M.

doi:10.1016/j.corsci.2005.05.054

Cited by 56 publications

(37 citation statements)

References 37 publications

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“…However, even when correlating these two, one should understand the sample bulk potential response as a quantity that results from the sequential mechanical depassivation and subsequent repassivation currents of infinitesimal bared or mechanically denuded specimen surfaces within the wear track at a given rate over the whole sliding cycle or period. Supporting evidence to the above is the good correlation between our model predicted potential values for Al alloys [6] and the OC potentials measured in the guillotined Al experiments reported in [5] within the appropriate time scale of ca. 0.1-1 s.…”

Section: Quantitative Prediction Of Potential Drop In Case Of Galvanisupporting

confidence: 59%

“…(referred there as OCP [5]), in their guillotined Al experiments, as in our case the wear track is not isolated and its potential is here monitored as the response from the surrounding cathode. However, even when correlating these two, one should understand the sample bulk potential response as a quantity that results from the sequential mechanical depassivation and subsequent repassivation currents of infinitesimal bared or mechanically denuded specimen surfaces within the wear track at a given rate over the whole sliding cycle or period.…”

Section: Quantitative Prediction Of Potential Drop In Case Of Galvanimentioning

confidence: 99%

“…Interesting approaches have appeared in the recent literature concerning the fundamental interpretation and the modeling of the repassivation kinetics during tribocorrosion [1][2][3] and the potential evolution with time for, e.g., freshly guillotined Al [4,5], but none-as far as the authors are aware-have treated or attempted theoretically to reproduce the complex behavior and the time evolution of the quasi steady-state depassivation-repassivation response of a tribocorrosion sliding experiment, where any perturbation in the potential occurs over the entire electrode surface and the response is a convolution of that from the passive metal surrounding the scratch and that from the relatively very thin scratch itself.…”

Section: Introductionmentioning

confidence: 99%

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Electrochemical Simulation of the Current and Potential Response in Sliding Tribocorrosion

Papageorgiou

Mischler

2012

Tribol Lett

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Valuable insights into the wear-corrosion behavior of metals, as well as into the tribocorrosion field through the development of simulation models of tribocorrosion experiments, can contribute in rationalizing wearaccelerated experiments and their open circuit potential (OCP) behavior under rubbing. These results demonstrate that mathematical models of controlled tribo-electrochemical contacts can complement the physical experiment and add valuable understanding to the tribological behavior of metals, alloys, and generally to materials in an electrochemically active environment. The excellent agreement of experimental wear data and the experimental OCP curves with the OCP simulations with time establishes the concepts underlying the galvanic coupling model as a valid methodological approach toward a quantitative description and mechanistic understanding of the tribo-electrochemical experiment. Besides analyzing stellite tribocorrosion, application of the model to Al alloy data has helped us quantify the relative contributions of chemical and mechanical wear and reveal the underlying synergy. Ti metal tribocorrosion under variable load has revealed that the contact pressure P av , can reach much lower values within the experimental time domain and finally be the cause of interruption of the initial wear mechanism.

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Section: Quantitative Prediction Of Potential Drop In Case Of Galvanisupporting

confidence: 59%

Section: Quantitative Prediction Of Potential Drop In Case Of Galvanimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Electrochemical Simulation of the Current and Potential Response in Sliding Tribocorrosion

Papageorgiou

Mischler

2012

Tribol Lett

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“…[19][20][21][22][23][24] This relationship between OCP and immersion time has been utilized to study the growth kinetics of oxide film formed on the bare metal surface [25][26][27][28][29][30][31] as well as at the coating/metal interface.…”

Section: 6mentioning

confidence: 99%

“…Burstein et al found that the corrosion potential of freshly generated aluminum increased linearly with the logarithm of immersion time during repassivation, which was interpreted to be correlated to the oxide film growth. [19][20][21][22][23][24] This relationship between OCP and immersion time has been utilized to study the growth kinetics of oxide film formed on the bare metal surface [25][26][27][28][29][30][31] as well as at the coating/metal interface. 32 Therefore, in this work the OCP method in combination with XPS and electrochemical impedance spectroscopy (EIS) techniques was applied to comprehensively explore the growth behavior of the EBinduced protective layer and to find out the difference to the growth process occurring without EB.…”

mentioning

confidence: 99%

Growth Behavior of Initial Product Layer Formed on Mg Alloy Surface Induced by Polyaniline

Luo

Wang

Guo

et al. 2015

J. Electrochem. Soc.

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The quality of the interfacial protective layer induced by polyaniline (PANI) has been claimed to play a crucial role for the enhanced corrosion protection of Mg alloy, but its growth behavior is not well understood. Here some composition, structure and growth kinetics of the protective layer formed at the PANI-emeraldine base (EB) coating/AZ91D Mg alloy interface were investigated to explore the growth mechanism. Upon immersion in 0.5 M NaCl solution, the growing interface layer under EB coating exhibited a fast passivation rate and an increased corrosion resistance, which was largely influenced by ion concentration. XPS depth profiles showed that the EB-induced layer was a mixture of MgO and Mg(OH) 2 , in which no significant bi-layer structure existed and MgO was dominant throughout the bulk film. These observations suggest that the interaction between EB and Mg can promote the faster growth of a stable MgO-rich layer mixed with Mg(OH) 2 probably by solid reaction. Meanwhile less hydration of MgO and dissolution-precipitation reaction occur, thus leading to less Mg(OH) 2 in the outer layer. Magnesium alloys have drawn great attention in automotive and aerospace industry due to their excellent properties such as low density and high specific strength. However, limited corrosion resistance of such alloys has retarded their widespread applications. To improve the corrosion resistance of Mg alloys, numerous coating techniques have been explored, among which organic coating containing corrosion inhibiting pigments is an economical and effective method in industry. One important pigment for Mg alloys is polyaniline (PANI) including emeraldine salt form (ES) and emeraldine base form (EB). 1-6Its highly efficient corrosion-protection performance for Mg alloys has been shown to be competitive to a chromate-pigmented coating. Additionally, self-healing capability was also found on a hybrid solgel/PANI coated Mg alloy upon immersing in Harrison's solution, where no pitting or filiform corrosion occurred around the scratched area while a protective layer was formed.8 Sathiyanarayanan et al. 1 and Wang et al. 8 observed that, after an initial decrease upon immersion in corrosive electrolytes, the complex impedance of PANI coated Mg alloy recovered, which was attributed to the formation of a protective layer. The different chemical composition on the EB-induced protective layer surface was already confirmed by X-ray photoelectron spectroscopy (XPS) in comparison with that formed underneath a varnish coating. 2,6The mechanism of PANI promoting a protective layer formation has been mostly supported by extensive studies in various metal systems.9-14 Nevertheless, few works have been done to understand the protective layer growth behavior. The most intractable issue of how the interaction between PANI and metal induces the protective layer growth still remains unsolved.9 This is attributed primarily to the great difficulty in in-situ investigation on the growth kinetics of interfacial layer formed beneath a coating. Electroche...

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In Situ Electrochemical Analysis during Deformation of a Zr‐Based Bulk Metallic Glass: A Sensitive Tool Revealing Early Shear Banding

et al. 2015

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In situ electrochemical experiments were carried out during quasi-static three-point bending of bulk glassy Zr 52.5 Cu 17.9 Ni 14.6 Al 10 Ti 5 alloy (Vit105) samples in air and in 0.01 M Na 2 SO 4 solution. Shear banding creating shear steps at surface break locally the naturally formed passive film resulting in a clear open circuit potential drop. Under potentiostatic polarization conditions, formation of shear steps causes narrow peaks in current density. By both methods, early shear banding can be detected before it can be inferred from macroscopic strain measurements.Most bulk metallic glasses (BMGs) show high strength values in combination with a large elastic deformation, which makes them very attractive for various applications. Concerning the quasi-static deformation behavior of fully amorphous bulk metallic glasses many investigations have been conducted and the versatile results are widely reported in literature. [1][2][3][4] But their lack of plasticity under mechanical loading, especially at tensile stresses, still poses an important drawback to their breakthrough as widely used structural materials. Particularly, the early stages of damaging are of great interest in this context. For this account, we developed a new technique taking advantage of discrete surface changes caused by shear banding, which are detectable by in situ electrochemical measurements. The prominent Zr-based BMG Vit105 was chosen as testing material in the current work, since it was identified as reliable target for complex mechanical analysis. [5] Versatile electrochemical investigations concerning the relation between corrosion and shear banding have been conducted for Zr-based amorphous alloys so far. In this context, Gebert et al. investigated the influence of mechanically generated surface defects on the pitting corrosion behavior of a Zr-based BMG in halide containing solutions. Moreover, they conducted a series of compression tests on samples with preformed corrosion pits to investigate the relationship between pitting and shear banding. [6] Wang et al. proposed a model which describes that pitting corrosion preferentially takes place at shear offsets. [7] Vit105 was recently analyzed concerning chemical breakdown events of the passive film without mechanical loading [8] and under static loading [9] both in a halide containing electrolyte. Since in the present study the pure deformation behavior of Vit105 bending samples is investigated, an inert 0.01 M Na 2 SO 4 solution was chosen for in situ electrochemical analysis. By the exploitation of the very sensitive electrochemical response of the Zr-based BMG to changes of the surface state, which are caused during deflection by the generation of small shear steps breaking the passive film, it is possible to detect and analyze the earliest stages of shear banding in situ during mechanical loading. ExperimentalThe Zr-based bulk glass-forming alloy Vit105 (Zr 52.5 Cu 17.9 -Ni 14.6

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Repassivation and pitting of freshly generated aluminium surfaces in acidic nitrate solution

Cited by 56 publications

References 37 publications

Electrochemical Simulation of the Current and Potential Response in Sliding Tribocorrosion

Electrochemical Simulation of the Current and Potential Response in Sliding Tribocorrosion

Growth Behavior of Initial Product Layer Formed on Mg Alloy Surface Induced by Polyaniline

In Situ Electrochemical Analysis during Deformation of a Zr‐Based Bulk Metallic Glass: A Sensitive Tool Revealing Early Shear Banding

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