CATHODIC DISBONDING OF INDUSTRIAL CHLORINATED RUBBER-BASED PRIMER USED IN RUBBER/METAL COMPOSITES: AN ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY ANALYSIS

2016 ◽  
Vol 89 (4) ◽  
pp. 712-723 ◽  
Author(s):  
I. Ismail ◽  
M. K. Harun
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Cathodic Polarization ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Time Interval ◽  
Significant Drop ◽  
Coating Degradation ◽  
Adhesion Failure ◽  
Bode Plots

ABSTRACT Chemlok 205 primer is a common bonding agent used together with a top coat in rubber/metal–bonded composites. Recent studies indicated that a stand-alone Chemlok 205 primer failed when its metal substrate underwent corrosion. The failure was suspected to be caused by coating degradation, followed by cathodic disbonding, induced from the corrosion reaction. Therefore, in this work, the effect of cathodic polarization on the coating delamination was further investigated. The work intends to focus on understanding the adhesion failure processes involved. Thus, electrochemical impedance spectroscopy (EIS) was employed on a stand-alone industrial coating Chemlok 205 primer on mild steel substrate subjected to cathodic polarization potential of −0.8 V versus Ag/AgCl reference electrode in 0.5 M NaCl. The coating barrier properties were interpreted through Nyquist and Bode plots of the EIS plots for a selected time interval. The data obtained were modeled against three distinguished electrical equivalent circuits representing the stages of coating degradation against time. Analysis through Nyquist and Bode plots indicated that the stand-alone Chemlok 205 primer coating experienced a significant drop in coating impedance before experiencing adhesion loss. The changes in the coating capacitance and coating resistance indicated that the coating underwent degradation first before adhesion failure.

scholarly journals Influencia del tipo de sinterizado en el comportamiento anticorrosivo de recubrimientos sol-gel

Respuestas ◽  
2016 ◽  
Vol 13 (2) ◽  
pp. 5-10
Author(s):  
Jorge Hernando Bautista-Ruiz ◽  
César Armando Ortiz-Otálora ◽  
Enrique Vera-Lopez
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Sol Gel ◽  
Dip Coating ◽  
Sintering Process ◽  
Properties Of Coatings ◽  
Corrosive Attack ◽  
Plasma Sintering

Este trabajo muestra un estudio electroquímico de recubrimientos SiO2 TiO2 ZrO2 obtenidos por el método sol-gel, sinterizados vía plasma y vía convencional. Los recubrimientos se conformaron a partir de Si(OC2H5)4, Ti(OBu)4 y Zr(OC3H7)4, se depositaron sobre sustratos de acero ANSI/304 mediante dip-coating en monocapa y bicapa. El proceso de densificado vía plasma se realizó a temperaturas del sustrato de 250 ºC, 300 ºC y 330 ºC y el convencional a 400 ºC y a una velocidad de calentamiento de 2 ºC/min. El comportamiento anticorrosivo se estudió mediante las técnicas de espectroscopía de impedancia electroquímica (EIS) y Tafel. Se observó que el proceso de sinterización vía plasma, mejora la resistencia a la corrosión con respecto al método convencional.Palabras Clave: sol-gel; corrosión; plasma; EIS;Tafel Abstract This work shows a comparative electrochemical study among the anticorrosive properties of coatings SiO2 TiO2 ZrO2 obtained by the method sol-gel and plasma sintering process and conventional. The coatings conformed to starting from Si(OC2 H5 )4 , Ti(OBu)4 and Zr(OC3 H7 )4 . These were deposited on steel substrate 304 by means of dip-coating in mono-layer and bi-layer. The plasma sintering process was carried out to temperatures of the substrate of 250 ºC, 300 ºC and 330 ºC and the conventional to 400 ºC and a speed of heating of 2 ºC/min. the anticorrosive behavior was studied by means of the techniques of electrochemical impedance spectroscopy (EIS) and Tafel. It was observed that the plasma sintering process, it improves the resistance to the corrosive attack to in regard to the conventional method.Keywords: sol-gel, corrosion, plasma, EIS, Tafel

scholarly journals Characterization of Biofilm Formation and Coating Degradation by Electrochemical Impedance Spectroscopy

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 518 ◽  
Author(s):  
Samanbar Permeh ◽  
Kingsley Lau ◽  
Matthew Duncan
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Microbial Activity ◽  
Electrochemical Impedance ◽  
Microbiologically Influenced Corrosion ◽  
Localized Corrosion ◽  
Steel Bridge ◽  
Surface Layers ◽  
Subsequent Formation ◽  
Coating Degradation

Recent findings showed severe localized corrosion of submerged steel bridge piles in a Florida bridge and was associated with microbial activity in the presence of marine foulers. Microbiologically influenced corrosion (MIC) can cause severe degradation of submerged steel infrastructure with the presence of biofilm associated with microorganisms such as sulfate reducing bacteria (SRB). Coatings have been developed to mitigate MIC and marine fouling. Coating degradation and disbondment can occur as a result of microbial attack due to the production of metabolites that degrade coating chemical and physical properties. In the work described here, electrochemical impedance spectroscopy (EIS) was conducted to identify microbial activity and degradation of an antifouling coating exposed to SRB-inoculated modified Postgate B solution. The measurements resulted in complicated impedance with multiple loops in the Nyquist diagram associated with the coating material, development of surface layers (biofilm), and the steel interface. Deconvolution of the impedance results and fitting to equivalent circuit analogs were made to identify coating characteristics and surface layer formation. EIS test results revealed coating degradation and subsequent formation of surface layers associated with SRB due to coating self-polishing and depletion of biocide components.

Effect of Doping of Nanoparticles on the Properties of Zn-Ni Composite Coatings

2018 ◽  
Vol 18 ◽  
pp. 19-26
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Khadidja Belassadi ◽  
Abdelouahed Chala ◽  
Malika Diafi
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Alloy Coating ◽  
Corrosion Performance ◽  
X Ray ◽  
Ni Alloy

The purpose of this paper was to investigate the effect of Al2O3 and TiO2 nanoparticles contents on structural proporties, microhardness and corrosion resistance of Zn-Ni alloy coationg. Zn-Ni, Zn-Ni-Al2O3 and Zn-Ni-TiO2 composite coatings were electrodeposited on steel substrate by direct current in sulphate bath.The structure of the coatings was studied by X-ray diffration and by scaning electron miroscopy. The results showed the appearance of Ni5Zn21 phases and that the incrorporation of Al2O3 and TiO2 in the Zn-Ni coating refined the crystal grain size.The corrosion performance of coating in the 0.6M NaCl as a corrisive solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy EIS methods. It was found that the incorporation of nanoparticules in Zn-Ni alloy coating have better corrosion resistance and the values of Rct and Zw increase, while the values of Cdl decrease with increasing of nanoparticules.

Studies on Estimating Methods of Polarization Performance for Coated Steel in Seawater

2010 ◽  
Vol 654-656 ◽  
pp. 2418-2421 ◽  
Author(s):  
Yu Hong Qi ◽  
Zhan Ping Zhang ◽  
Mei Miao ◽  
Xia Zhen Zhang
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Potential Distribution ◽  
Cathodic Polarization ◽  
Electrochemical Impedance ◽  
Electrochemical Measurement ◽  
Coated Steel ◽  
Coating Properties ◽  
Polarization Data ◽  
Measured Polarization

The polarization curves and electrochemical impedance spectroscopy of coated steel after scratching cross-lines or cathodic polarization using COLT system connected to electrochemical workstation IM6ex in seawater are investigated and from the measured polarization data, potential distribution on hull surface under waterline are predicted using Beasy CP software. It is shown that an more pricise method for gaining polarization data of the coated steel in seawater is the electrochemical measurement carried out by COLT system and the method of scratching cross-lines or cathodic polarization for coating damage is simple and convenient for estimating the polarization data of a new coated hull that is closely related to the coating properties.

Effect of Manganese Ions on Corrosion Inhibition of PANI for Mild Steel in 0.5 M H2SO4

2011 ◽  
Vol 415-417 ◽  
pp. 174-177
Author(s):  
Yu Qiu Huo ◽  
Ling Bai
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Manganese Ions ◽  
Mild Steel Substrate

Manganese ions doped Pani films were prepared by using a cyclic voltammetry technique on mild steel substrate. Corrosion resistances performances of them in 0.5 M H2SO4 solution were obtained by using electrochemical impedance spectroscopy (EIS), polarization curve, and SEM method. The results showed that manganese ions doped Pani particles became smaller and tighter, the resistance reduced, and the corrosion potential rose than Pani in H2SO4 solution.

scholarly journals Chemical Degradation of Epoxy-Polyamide Primer by Electrochemical Impedance Spectroscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Ramesh Duraisamy ◽  
Kannan Pownsamy ◽  
Ghebray Asgedom
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Epoxy Resin ◽  
Hybrid Material ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Physical Phenomenon ◽  
Chemical Degradation ◽  
Transfer Resistance ◽  
Circuit Components

The degradation of organic-inorganic hybrid materials based on epoxy resin was characterized electrochemically in aggressive chemical electrolyte. In the present study, the hybrid material as primer was prepared from epoxy resin pigmented by zinc phosphate cured with polyamide (EPZ). The hybrid material was coated on mild steel substrate, and the corrosion behavior was studied by electrode-potential time measurements and mainly by electrochemical impedance spectroscopy (EIS) in 5% NaCl solution. The impedance parameters, namely, coating capacitance (), pore resistance (), charge transfer resistance (), double layer capacitance (), and break point frequency (), corresponding to 45° phase angle as a function of time of exposure were estimated. The observed impedance behavior were compared with the established equivalent electrical circuit represents the coated metal/electrolyte interface. Changes in the values of the circuit components given the information on the stages of degradation and physical phenomenon occurring throughout the degradation of primer coating were also been predicted. In addition, information related to the porous nature of the primer, limited passivation effect, and delamination of coating with longer exposure that resulted in the diffusion controlled corrosion of metal are also recognized. Thus, results indicate that the EPZ coating had good corrosion resistance. This could be a nonpolluting alternative to the traditional chromate like environmentally harmful coatings.

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