Application of Laplace Equation-Based Modeling into Corrosion Damage Prediction for Galvanic Coupling Between a Zinc Plate and Stainless Steel Rods Under a Thin Film Electrolyte

Liu, Chao; Kubacki, Gregory W.; Kelly, Robert G.

doi:10.5006/2969

Cited by 15 publications

(9 citation statements)

References 23 publications

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“…However, their work considered an unchanged solution concentration of constant conductivity, which reduces the applicability of the model for wet-dry cycles. In another work, Liu et al [20] modelled the corrosion damage prediction for galvanic coupling between a zinc plate and stainless-steel rods under a thin film electrolyte. However, the same assumption of constant electrolyte conductivity in one run of simulation was applied.…”

Section: The Current Status Of Fem Thin Film Corrosion Modelling: Where We Advanced?mentioning

confidence: 99%

Finite Element Method for Thin Film Corrosion Modelling: Where We Advanced and Where We would like to Advance?

Saeedikhani

Blackwood

2020

CMD

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Thin film corrosion is a serious issue in almost every sector. Thus, simulation of corrosion under thin electrolyte films has always been of high interest as experimental studies are often challenging. Thus far, progress has been made to model the effect of several important factors on thin film corrosion rates. Some of these parameters are electrolyte thickness, electrolyte composition, chemical reactions in the electrolyte, electrode size and change in electrode size, environmental parameters, and corrosion products deposition. However, these parameters are mainly drawn from different studies and have not been modelled concurrently in a single simulation study, making the thin film corrosion model far from being complete yet. Therefore, despite the many efforts so far, thin film corrosion modelers still strive to push the modelling edges further. This paper takes into account some of the highlighted recent advances in thin film corrosion modelling based on the mentioned parameters to provide a perspective on not only how far the field has come, but also how far it still is from a complete thin film corrosion model. Discussions have also been made on future needs and prospects to advance the thin film corrosion models further.

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Section: The Current Status Of Fem Thin Film Corrosion Modelling: Where We Advanced?mentioning

confidence: 99%

Finite Element Method for Thin Film Corrosion Modelling: Where We Advanced and Where We would like to Advance?

Saeedikhani

Blackwood

2020

CMD

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“…This testing environment is very common for evaluating the effects of corrosion damage within a galvanic couple. 3,18,[22][23][31][32]34 Although this test is known to be much more aggressive than most service conditions, and cannot predict specimen lifetimes, 34 it has become a standard and results from it can be gathered and compared with other data from the literature. This test consists of a continuous vertical spray of 5% NaCl salt water, which creates a fog over the samples mounted at a 15°tilt, while the temperature and humidity remain constant.…”

Section: Accelerated Testingmentioning

confidence: 99%

“…This assumption has been made in finite element models before. 4,6,10,12,18,35 The current distribution was calculated in the model and was converted to anodic charge in order to compare with experimental data. Rather than multiplying the current by the total amount of time which the experimental samples were exposed to the testing environment (504 h in our case), a 4-d "initiation" period for corrosion was accounted for.…”

Section: Finite Element Modelingmentioning

confidence: 99%

“…Much modeling research has been done on the galvanic coupling of dissimilar metals in simple geometries. [4][5][6]9,14,18 However, less modeling research has been done on more complex geometries, such as panel/fastener assemblies, 8,[11][12][19][20] which are more common in real-life situations and are known to trap water in crevices between dissimilar metals. [21][22] The complex geometry of structural components in the aircraft increases the difficulty in both experimental measurement and modeling of the galvanic couple.…”

Section: Introductionmentioning

confidence: 99%

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Galvanic Corrosion Between Coated Al Alloy Plate and Stainless Steel Fasteners, Part 1: FEM Model Development and Validation

et al. 2019

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Aerospace structures often involve dissimilar materials to optimize structural performance and cost. These materials can then lead to the formation of galvanic couples when moisture is present. Specifically, noble metal fasteners (such as SS316) are often used in aluminum alloy load-bearing structures, which can lead to accelerated, localized corrosion attack of the aluminum alloy due to the cathodic current supplied by the SS316 fastener. This localized attack is difficult to predict, and tests are often expensive, so modeling of these galvanic couples could be of great utility. The work reported here focuses on the galvanic coupling between fasteners installed in a panel test assembly, and the resultant corrosion damage down the fastener holes. This arrangement is a common assembly geometry in aerospace applications. A specific sol-gel coating was applied to the fasteners, to determine its effectiveness on mitigating galvanic corrosion; bare fasteners were also tested, to investigate a worst-case scenario. Geometric constraints in the model were made to match those of an experimental test panel, which was exposed to ASTM B117 salt fog for 504 h. The electrochemical boundary conditions were generated in solutions appropriate to the material and environment to which it would be exposed. Anodic charge passed during exposure was calculated from image analyses of the corrosion damage in the experimental test, and the results were compared with the model. The Laplacian-based model provides a very good first approximation for predicting the damage within the fastener hole. Validation was provided by both experimental results generated in this study as well as comparison to results in the literature that used similar, but not identical, conditions.

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“…The solution of Laplace's equation in calculating the coatings of steel products used in aviation can be obtained using the COMSOL Multiphysics software package 1,2 . The disadvantage of the models used is that they do not take into account the electrochemical processes occurring near the surface of the cathode and anode are their linearity.…”

Section: Introductionmentioning

confidence: 99%

Modeling of metal distribution when coating flat metal plates in electroplating baths

Pchelintseva

Pchelintsev

Litovka

2020

Int J Numerical Modelling

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Electrolytic metal coating processes are used to protect products from corrosion, decorative surface finish and other purposes. Electroplated coating has an important quantitative characteristic, which is coating thickness. Since the electric field in the electrolyte is not uniform, the coating thickness at different points on the surface of detail is different. An important task here is to apply a more uniform coating. To solve this problem, it is necessary to calculate the distribution of potentials in a galvanic bath from Laplace's equation. The study aims to increase the convergence rate of the numerical procedure in order to solve Laplace's equation with nonlinear boundary conditions by developing a numerical scheme based on Newton's method. Based on a numerical solution of Laplace's equation with nonlinear boundary conditions describing the potential distribution in a galvanic bath, the thickness of the nickel deposition layer on the surface of a flat metal cathode plate was calculated for different sizes of galvanic baths and anode voltages. A feature of the numerical calculation scheme is the use of Newton's method for the approximate solution of the resulting system of nonlinear algebraic equations with a given accuracy. The obtained results show the effectiveness of the applied numerical method: the quadratic convergence rate of Newton's method gives a time gain of 10 times in comparison with one of the best numerical methods for this type of problem.

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Application of Laplace Equation-Based Modeling into Corrosion Damage Prediction for Galvanic Coupling Between a Zinc Plate and Stainless Steel Rods Under a Thin Film Electrolyte

Cited by 15 publications

References 23 publications

Finite Element Method for Thin Film Corrosion Modelling: Where We Advanced and Where We would like to Advance?

Finite Element Method for Thin Film Corrosion Modelling: Where We Advanced and Where We would like to Advance?

Galvanic Corrosion Between Coated Al Alloy Plate and Stainless Steel Fasteners, Part 1: FEM Model Development and Validation

Modeling of metal distribution when coating flat metal plates in electroplating baths

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