Electrochemical noise (EN) technique: review of recent practical applications to corrosion electrochemistry research

Abstract

The ability to analyze different electrochemical corrosion phenomena, in-situ, without requiring any form of electrode perturbation has strongly attracted the attention of corrosion researchers towards the application of electrochemical noise (EN) analysis method. With the ability to analyze stochastic and chaotic electrode potential and current fluctuations at E OCP , the EN analysis method is capable of providing information about the kinetics and mechanism of metallic corrosion with accuracy that can match conventional electrochemical techniques. Herein, we review the recent applications of EN analysis method to electrochemical corrosion research. We discuss briefly the theory behind the measurement of EN, and then highlight some of its application in the evaluation of corrosion inhibitors, pitting corrosion, coatings on metals, microbiologically-induced corrosion, as well as CO 2-corrosion. The drawbacks of the EN analysis method have also been highlighted and future considerations on the use of this important electrochemical technique have also been proposed.

Pitting Corrosion behaviour of Austenitic Stainless-Steel Coated on Ti6Al4V Alloy in Chloride Solutions

“…The samples' electrochemical characterization and corrosion behaviour were studied using the potentiodynamic polarization as a function of time, in a chloride solution with two concentrations of 0.9 and 3.5 wt. % of NaCl at 25 o C, which is similar to the human body environment [18][19][20][21]. The electrochemical tests were performed using a model Bio-Logic SP-150 potentiostat measuring instrument.…”

“…The results showed that coating of 316L on Ti alloy reduced the wear rate of the powder alloy. In terms of the biocompatibility tests of coating austenitic stainless-steel alloy on Ti alloys, recent investigations [18,19] show that there is a relationship between pitting corrosion resistance and microbiologically induced corrosion (MIC), based on the similarities of the localized corrosion of MIC in nature, which is the phenomena of pitting and crevice corrosion. The previous paper of the author [17] indicates that the coated Ti6Al4V with 316L powder alloy, were tested in a bacterial environment of E. coli and S. aureus bacteria, and the results showed good antibacterial properties, no bacteria observed on the surface of 316L.…”

Surface electroanalytical approaches to organic polymeric coatings

“…EN is a sensitive and nondestructive technique employed to simultaneously measure potential and current fluctuations as noise produced by the anodic and cathodic reactions. 32,33,[61][62][63][64] For polymer-coated metals, the current noise indicates changes in coating integrity, while the potential noise indicates passivity and the presence of electrolyte at the coating-metal interface. 22,65 A typical experimental setup is shown in Fig.…”

“…25,26 Techniques that measure impedance and the correlation between current, potential and time have been widely used to obtain mechanistic information on corrosion. 15,17,[27][28][29][30][31][32][33][34][35][36][37][38] Hence, this mini-review briefly explores the most commonly used electrochemical techniques in the evaluation of corrosion protection performance of polymeric coatings: open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, electrochemical noise and scanning electrochemical microscopy (SECM). The mode of operation, acquisition of data, relevant equations and electrochemical variables, as well as the advantages and shortcomings of each technique, are also highlighted.…”

Frontiers and Challenges in Electrochemical Corrosion Monitoring; Surface and Downhole Applications

“…Although this hope has not been fully implemented but there has been some progress and the technique has been in use for corrosion monitoring. EN analysis is a reliable technique that allows metal corrosion determination without any kind of external potential perturbation [ 63 ]. EN is more suited to detect and quantify localized corrosion [ 60 ].…”