Mathematical model for cathodic delamination using a porosity–pH relationship

Allahar, Kerry N.; Orazem, Mark E.; Ogle, K.

doi:10.1016/j.corsci.2007.03.024

Cited by 32 publications

(54 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first comprehensive mathematical model for cathodic delamination comprising of a non-linear porosity-pH relationship was developed by Allahar et al [128,129] based upon the experimental results [113][114][115][116][117][118][119][120]. The interfacial porosity which depends on hydroxyl OH-ions formation decides the interfacial bonding and bond breakage of film and substrate [130].…”

Section: Cathodic Delaminationmentioning

confidence: 99%

A review of theoretical analysis techniques for cracking and corrosive degradation of film-substrate systems

Nazir

Khan

2017

Engineering Failure Analysis

View full text Add to dashboard Cite

This paper contains a review of the most vital concepts regarding the analysis and design of film systems. Various techniques have been presented to analyse and predict the failure of films for all common types of failure: fracture, delamination, general yield, cathodic blistering, erosive and corrosive wear in both organic and inorganic films. Interfacial fracture or delamination is the loss of bonding strength of film from substrate, and is normally analysed based on the fracture mechanics concepts of bi-material systems. Therefore, keeping the focus of this review on bonding strength, the emphasis will be on the interfacial cracking of films and the corresponding stresses responsible for driving the delamination process. The bi-material characteristics of film systems make the nature of interfacial cracks as mixed mode, with cracks exhibiting various complex patterns such as telephone cord blisters. Such interfacial fracture phenomenon has been widely studied by using fracture mechanics based applicable analysis to model and predict the fracture strength of interface in film systems. The incorporation of interfacial fracture mechanics concepts with the thermodynamics/diffusion concepts further leads to the development of corrosive degradation theories of film systems such as cathodic blistering. This review presents the suggestions for improvements in existing analysis techniques to overcome some of the limitations in film failure modelling. This comprehensive review will help researchers, scientists, and academics to understand, develop and improve the existing models and methods of film-substrate systems.

show abstract

Section: Cathodic Delaminationmentioning

confidence: 99%

A review of theoretical analysis techniques for cracking and corrosive degradation of film-substrate systems

Nazir

Khan

2017

Engineering Failure Analysis

View full text Add to dashboard Cite

show abstract

“…When the time constant associated with the metal-coating bond breakage is small, the migration and the diffusion rate of ionic species into the delaminated region is also small. [17] However, Allahar [16], Huang [17], Stratmann [3,7] and Leng [9,11] investigations did not cover the effect of environmental parameters such as: temperature variations (T), time of exposure (t exp ) and pore relative humidity (RH). Allahar modelled the polarisation kinetics, influenced by just oxygen reduction reaction without the influence of environmental parameters (T, RH and t exp ).…”

Section: Introductionmentioning

confidence: 99%

“…His further findings showed that the corrosion rate decreases with the large concentration of ionic species diffusing through the defect resulting in the passivation and making the active metal sites to appear beneath the metal-coating. Allahar [16] developed a mathematical model based upon the experimental results of Stratmann and further extended his research work and designed a non-linear porosity-pH relationship. Based upon Allahar's approach, Huang [17] investigated that the OH -ions along the metal-coating interface decide the propagation of metal-coating delamination; his further investigation showed that the delamination rate depends upon the metal-coating bond breakage.…”

Section: Introductionmentioning

confidence: 99%

A holistic mathematical modelling and simulation for cathodic delamination mechanism – a novel and an efficient approach

Nazir

Khan

Stokes

2015

Journal of Adhesion Science and Technology

View full text Add to dashboard Cite

This paper addresses a holistic mathematical design using a novel approach for understanding the mechanism of cathodic delamination. The approach employed a set of interdependent parallel processes with each process representing: cation formation, oxygen reduction and cation transport mechanism, respectively. Novel mathematical equations have been developed for each of the processes based on the observations recorded from experimentation. These equations are then solved using efficient time-iterated algorithms. Each process consists of distinct algorithms which communicate with each other using duplex channels carrying signals. Each signal represents a distinct delamination parameter. As a result of interdependency of various processes and their parallel behaviour, it is much easier to analyse the quantitative agreement between various delamination parameters. The developed modelling approach provides an efficient and reliable prediction method for the delamination failure. The results obtained are in good agreement with the previously reported experimental interpretations and numerical results. This model provides a foundation for the future research within the area of coating failure analysis and prediction.

show abstract

“…Up to now our knowledge about the reactions and how they are determined by the interface itself is too restricted to be able to make reliable prediction about interfacial degradation rates, although first attempts, albeit based on experimental input parameters, have been tried. 10 An important question is how the electrochemical reactivity of such metal/polymer coated systems is determined by the interfacial chemistry of the metal oxide/coating interface. As an example, using XPS, Wielant et al 11 showed that a large fraction of hydroxyls present on the oxide surface aided bonding of amine/amide based model compounds through nitrogen protonation.…”

mentioning

confidence: 99%

Probing the Buried Metal-Organic Coating Interfacial Reaction Kinetic Mechanisms by a Hydrogen Permeation Based Potentiometric Approach

Vijayshankar

Altin

Merola

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

Corrosion driven delamination of coatings is crucially determined by the rate of the cathodic oxygen reduction reaction at the buried metal-organic coating interface. Quantitative measurement of this rate at such interfaces by conventional techniques is impeded due to the blocking of ion transport by the coating. A new approach where hydrogen permeation is used as a tool to measure the oxygen reduction rate underneath coatings has been recently introduced. This permeation based potentiometry approach measures the rate of the oxygen reduction reaction by correlating the open circuit potential established as a consequence of the dynamic electrochemical equilibrium between hydrogen oxidation and oxygen reduction reactions on the coated exit side with the hydrogen uptake rate on the entry side. In this work, the interfacial reaction kinetics of the oxygen reduction reaction causing delamination of the coating are investigated by this hydrogen permeation based potentiometric approach. Moreover, thus performed prolonged cathodic polarizations of the palladium/coating interface have been found to destroy the interface, just like it is the case in the cathodic delamination process. Initial results obtained on ultra-thin films of iron on palladium are also presented, showing that the technique is applicable also on technically more relevant metal surfaces. Corrosion driven degradation of the buried metal/organic coating interface is of utmost interest in the contemporary space of coatings science. Earlier studies have shown conclusively that the oxygen reduction reaction (ORR) plays a fundamental role in the destruction of this buried metal/organic coating interface. The role of the interface between organic coating and metal has been object of intense research over last decades. Leidheiser et al.1 pointed out the key role of the cathodic ORR for the degradation process and also showed that diffusion processes such as water and oxygen transport through the coating can influence this delamination rate. Stratmann and co-workers 2-4 proposed a detailed delamination mechanism for a basic polymer coating on steel where galvanic coupling between the defect site of metal dissolution (local anode) and delamination site of electrochemical oxygen reduction (local cathode) supported by cation migration along the polymer/metal interface lead to the progressive deadhesion of the polymer from the underlying metal based on comprehensive analysis of the local electrode potential at the metal/polymer interface using primarily the Scanning Kelvin Probe (SKP) technique along with complementary Auger electron spectroscopy and mechanical deadhesion tests. Fürbeth and Stratmann 5-7 extended their studies to coated zinc (or galvanized steel), which also involves anodic processes at the interface. Also other works by Brewis et al. 8 and Dickie et al. 9 show the importance of interfacial electrochemical reactions on metal/polymer adhesion. Up to now our knowledge about the reactions and how they are determined by the interface itself is too rest...

show abstract

Mathematical model for cathodic delamination using a porosity–pH relationship

Cited by 32 publications

References 12 publications

A review of theoretical analysis techniques for cracking and corrosive degradation of film-substrate systems

A review of theoretical analysis techniques for cracking and corrosive degradation of film-substrate systems

A holistic mathematical modelling and simulation for cathodic delamination mechanism – a novel and an efficient approach

Probing the Buried Metal-Organic Coating Interfacial Reaction Kinetic Mechanisms by a Hydrogen Permeation Based Potentiometric Approach

Contact Info

Product

Resources

About