Electrochemical Behavior Of Brass Research Articles

Protection of Brass in HCl Solution by L-Cysteine and Cationic Surfactant

Electrochemical behavior of brass and inhibitory effect of L-cysteine in HCl solution are investigated using electrochemical techniques in addition to SEM-EDS analysis. Results show that inhibition efficiency depends on inhibitor concentration and immersion time of brass electrode in inhibitor solution. Electrochemical test results point to formation of Cu(I)-cysteine complex on the brass surface in chloride solutions with addition of different amounts of cysteine. The formed complex has an important role in inhibition of the corrosion process in the examined media because Cu(I)-cysteine significantly reduces dissolution of brass. Curves obtained in acidic solution in the presence of cysteine after pretreatment in sodium dodecyl sulfate (SDS) by cyclic measurements and potentiodynamic polarization measurements indicate intense inhibition of corrosion processes. Efficient inhibition of brass dissolution is result of formation of a stable protective layer on the brass surface after pretreatment of the electrode in SDS solution. The brass surface is modified in sodium dodecyl sulfate solution in order to increase cysteine adsorption on the electrode surface and to improve inhibition efficiency. Inhibition mechanism of cysteine includes adsorption on active sites on the electrode surface, which is confirmed by SEM-EDS analysis of brass. Adsorption of cysteine in hydrochloric acid solution obeys the Langmuir adsorption isotherm. Also, Gibbs free energy of adsorption has a value of −31.5 kJ/mol and indicates strong adsorption of cysteine on the electrode surface.

2-Amino-5-ethyl-1,3,4-thiadiazole as inhibitor of brass corrosion in 3% NaCl

The electrochemical behaviour of brass and anticorrosion effect of 2-amino-5- ethyl-1,3,4-thiadiazole (AETD) in chloride solution was investigated using electrochemical techniques. Results show that inhibition efficiency depended on inhibitor concentration and immersion time of brass electrode in inhibitor solution. Mechanism of brass corrosion inhibition by 2-amino-5-ethyl-1,3,4-thiadiazole includes adsorption of inhibitor on active sites on electrode surface. Adsorption of AETD in 3% NaCl solution obeys Langmuir adsorption isotherm.

Inhibition of Brass Corrosion by 2-Mercapto-1-methylimidazole in Weakly Alkaline Solution

The electrochemical behavior of brass and anticorrosion effect of 2-mercapto-1-methylimidazole (2-MMI) in weakly alkaline solution with and without presence of chloride ions was investigated using electrochemical techniques in addition to SEM-EDS analysis. Results show that inhibition efficiency depended on inhibitor concentration and immersion time of brass electrode in inhibitor solution. Inhibition mechanism of 2-mercapto-1-methylimidazole includes adsorption of inhibitor on active sites on electrode surface which was confirmed by SEM-EDS analysis of the brass. Adsorption of the 2-MMI in sodium tetraborate solution obeys Flory-Huggins adsorption isotherm, while in the presence of chloride, ions adsorption of inhibitor obeys Langmuir adsorption isotherm.

Predicting the corrosion tendency of α-brass in acidic and alkaline tap water

AbstractThis study focuses on the electrochemical behavior of brass in acidic and alkaline tap water. Both conditions were studied using corrosion potential, cyclic polarization and electrochemical impedance spectroscopy. Weight loss experiments were also performed to validate corrosion behavior. It was evaluated from corrosion potential values and Pourbaix diagrams that brass surface was aggressively attacked at lowpHdue to dissolution of zinc-rich phase and solvation of cuprite and zincate at highpHby breakdown of the passive film. Under near neutral conditions the increase in charge transfer resistance corresponded to formation of a stable passive film. Brass exhibited peculiar behavior atpH1 and 12 by showing low charge transfer resistance due to preferential attack of zinc and solvation of copper/zinc rich phases, respectively, as validated by impedance spectroscopy.

Electrochemical behaviour of brass in chloride solution concentrations found in eccrine fingerprint sweat

Abstract In this work, the corrosion properties of α phase brass immersed in concentrations of aqueous NaCl solutions that are typically found in eccrine fingerprint sweat and range between 0.01 M and 0.2 M have been analysed. Analysis methods employed were electrochemical techniques, X-ray photoelectron spectroscopy and optical profiling. For NaCl concentrations

The Electrochemical Behaviour of Brass in NaHSO3Solution Without and With Cl-

The Electrochemical Behaviour of Brass in NaHSO3Solution Without and With Cl-

Electrochemical Adsorption Properties and Inhibition of Brass Corrosion in Natural Seawater by Thiadiazole Derivatives: Experimental and Theoretical Investigation

The electrochemical behavior of brass in natural seawater in the absence and presence of thiadiazole derivatives, namely, 2-amino-5-(4-methoxyphenyl)-1,3,4-thiadiazole (AMOPTD), 2-amino-5-(4-methylphenyl)-1,3,4-thiadiazole (AMPTD), 2-amino-5-(4-pyridinyl)-1,3,4-thiadiazole (APTD), and 2-amino-5-(4-nitrophenyl)-1,3,4-thiadiazole (ANPTD), has been investigated by electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The optimum concentration of the studied inhibitors showing the highest inhibition efficiency was also evaluated at five different temperatures in the range between 303 and 343 K. The inhibition efficiency was found to increase with increase in concentration of the inhibitors but decrease with rise in temperature for all the studied inhibitors except ANPTD. Thermodynamic and kinetic parameters for the adsorption process were determined. Quantum chemical approach was further used to calculate some electronic properties of the molecule in...

Effect of Some Oxadiazole Derivatives on the Corrosion Inhibition of Brass in Natural Seawater

The electrochemical behavior of brass in natural seawater in the absence and presence of oxadiazole derivatives, namely 2,5-bis-(4-aminophenyl)-1,3,4-oxadiazole (BAPOD), 2,5-bis-(4-bromophenyl)-1,3,4-oxadiazole (BBPOD), 2,5-diphenyl-1,3,4-oxadiazole (DPOD), and 2,5-bis-(4-nitrophenyl)-1,3,4-oxadiazole (BNPOD) has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The inhibition efficiency of the inhibitors was also evaluated at different temperatures. The inhibition efficiency was found to increase with increase in concentration of the inhibitors but decrease with rise in temperature for all the inhibitors except BNPOD. Inductively coupled plasma atomic emission spectroscopic (ICP-AES) analysis confirmed that dezincification was minimized to a greater extent in the presence of the inhibitors. Scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX) and Fourier transform infrared spectroscopy (FT-IR) observations of the brass surface confirmed the existence of an adsorbed film.

Influence of pH and Chlorides on Electrochemical Behavior of Brass in Presence of Benzotriazole

Influence of pH and Chlorides on Electrochemical Behavior of Brass in Presence of Benzotriazole

The effect of phosphate ions on the electrochemical behaviour of brass in sulphate solutions

In this study, we have investigated the effect of phosphate ions on the corrosion behaviour of brass in 0.1 M Na 2SO 4 solution in acidic (pH 2.1), neutral (pH 7.2) and alkaline (pH 12.3) solutions. For this purpose, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) techniques were used. The surface morphology of the metal surface after exposed to corrosive medium was investigated by scanning electron microscopy (SEM). The effect of temperature has also studied in the temperature range from 293 K to 353 K. Some thermodynamic parameters were calculated and discussed. It was found that, PO 4 3− ions could inhibit the corrosion of brass in Na 2SO 4 solution. However, the inhibition efficiency decreased with increasing temperature. The inhibition effect of PO 4 3− ions was explained by complex formation between phosphate ions and corrosion products which physically adsorbed on the metal surface.

Influence of pH and Chloride Ions on Electrochemical Behavior of Brass in Alkaline Solution

Influence of pH and Chloride Ions on Electrochemical Behavior of Brass in Alkaline Solution

The effects of acetate ions on electrochemical behaviour of brass in chloride solutions

The corrosion behaviour of brass (67% Cu, 33% Zn) was investigated in chloride solutions, in the presence of acetate ions. For this aim, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements were utilized. The pH of solution was adjusted to 8.5. It was shown that, CH 3COO − ions could inhibit anodic dissolution of brass in aggressive chloride media. The effect of temperature was also studied in a range between 298 and 328 K. The inhibition effect of acetate ions was resulted from complex formations (between acetate ions and corrosion products) which physically adsorbed on the surface. The inhibition efficiency decreased with the temperature. The results obtained at different temperatures were used to evaluate various thermodynamical properties.

Electrochemical behaviour of brass in artificial seawater: effect of organic inhibitors

The electrochemical behaviour of brass was studied in artificial seawater with two organic inhibitors namely N,N-dibenzotriazol-1-ylmethylaminomethane (DBMM) and 3-hydroxypropyl benzotriazole (HPBT) using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), cyclic voltammetry and current transient techniques. Preliminary screening of the inhibition efficiency (IE) was carried out using weight-loss measurements. Polarization measurements showed that the organic compounds investigated are mixed type inhibitors, inhibiting the corrosion of brass by blocking the active sites of the metal surface. Changes in the impedance parameters (charge transfer resistance (Rct) and double layer capacitance (Cdl)) are related to adsorption of organic inhibitors on the metal surface, leading to the formation of a protective film, which grows with increasing exposure time. Cyclic voltammetric studies confirmed that the addition of inhibitors effectively inhibits the anodic dissolution of brass in artificial seawater.

Effect of Zn and Pb as alloying elements on the electrochemical behavior of brass in NaCl solutions

The electrochemical behavior of brasses with various Zn content (5.5–38 mass%) and brass (Cu–38Zn) with different Pb contents (1–3.4 mass%) in 0.6 M NaCl was investigated. The effects of temperature, immersion time, and concentration of chloride ions on the behavior of the different alloys were studied. The pitting corrosion behavior of Cu–Zn alloys and leaded–brass alloys in 0.6 M NaCl solution was also investigated. Open-circuit potential measurements (OCP), polarization techniques and electrochemical impedance spectroscopy (EIS) were used. The results show that the increase in the Zn content increases the corrosion rate of the brass alloys in chloride solutions, while the increase of Pb content in Cu–38Zn–Pb decreases the corrosion rate of the alloy. Long immersion time of the alloys in the aqueous electrolyte improves their stability due to the formation of passive film on the alloy surface. The breakdown potential is shifted to more negative direction with increasing the Zn content, whereas it shifts towards positive values with increasing Pb content. Equivalent circuit model for the electrode/electrolyte interface under different conditions was proposed to illustrate the electrochemical processes taking place at the interface. The electrochemical behavior of the different alloys was discussed in view of the fitting results.

Electrochemical behavior of brass in 0.1 M NaCl

The corrosion behavior of brass in 0.1 M NaCl was investigated with voltametric technique. For comparison the behaviors of pure components of the alloy was investigated under the same condition. Evaluation of the solution analysis with the voltametric curves shows that initial dissolution takes place at about −1.0 V (SCE) as ZnO and zinc ions. The dissolution of copper as ions is prevented by the exchange reaction between them. This prevention continues up to CuCl formation potential. Even in the passivity region of brass, dissolution of zinc continues with anodic polarization.

Electrochemical Behavior of Brass in Acid Solutions and the Inhibitive Effect of Imidazole

A new voltammetric method has been proposed to determine the corrosion rates of brass in 2N HCl and H 2 SO 4 solutions with and without imidazole inhibitor in short periods of time. Significantly, it has also been possibleto determine the corrosion rates simultaneously with respect to Cu(II) and Zn(II). These results have been compared with the average corrosion rates obtained using the gravimetric (weight loss) method and some electrochemical methods like galvanostatic and potentiodynamic polarization measurements.

Effects of Zn and Pb as alloying elements on the electrochemical behaviour of brass in borate solutions

The electrochemical behaviour of brasses with various Zn content (5.5–38) and brass (Cu–38Zn) with different Pb content (1.3–3.3) in borate solution, pH 9.0, was investigated. The effects of applied potential and the presence of aggressive Cl− ions were also studied. Different electrochemical methods such as open-circuit potential measurements, polarization techniques and electrochemical impedence spectroscopy (EIS) were used. Increase in zinc content decreases the corrosion rate of brass in borate solution exponentially. Long immersion of leaded brasses and alloys with different Zn content improves their stability due to the formation of a passive film. The passive film formation under open-circuit and potentiostatic conditions proceeds via dissolution–precipitation mechanism. The addition of a low concentration of Cl− ion (0.01 M) to the borate solution increases the corrosion rate of Cu–38Zn due to dezincification. Increase in Cl− ion concentration (0.01–0.2 M) decreases the corrosion rate of the brass exponentially due to formation of insoluble CuCl. For Cl− ion concentrations >0.2 M the corrosion rate of the brass increases again due to the formation of the soluble CuCl2 − complex.

The electrochemical behavior of brass in 0.1 M HCl solution

The electrodissolution of commercial brass (60.8Cu-36.3Zn-2.9Pb) and pure copper in 0.1 M HCl were comparatively studied using cyclic voltammetry and a rotating ring-disk electrode. The dissolution mechanism of both specimens presents distinct kinetic parameters. However, the dissolution mechanism of the Cu component of brass is the same as that observed for pure copper.

Electrochemical behaviour of brass (Cu/Zn, 63/37) in binary mixtures of acetonitrile and water

Electrochemical behaviour of commercial brass, 63/37 (Cu/Zn) in acetonitrile (AN) and water mixtures of varying compositions ( ie 2–100 m/o AN) at 30°C has been studied using accelerated weight loss method, solution analysis and potentiostatic polarization technique. It is found that during anodic polarization brass exhibits an active-passive transition in 2, 5, 10, 2o and 30 m/o AN, while no passivity has been observed in 50, 70, 95 and 100 m/o AN. Further the dissolution of brass has been found to be cathodically controlled. The open-circuit potential measurements show that as AN content in the solvent mixture increases, both immersion as well as steady potentials gradually shift towards less noble direction. The weight loss and solution analysis show preferential dissolution of zinc in the initial stages which progressively decreases with time.

Electrochemical Behavior of Brass (CuZn 63:37) in Binary Mixtures of N,N-Dimethylformamide and Water

Abstract The electrochemical behavior of brass has been studied In N,N-dimethylformamide (DMF) and water mixtures at 30 C using the potentiostatic polarization technique, weight loss method, and solution analysis. The effects of dissolved oxygen and stirring have also been studied. The dissolution of brass has been found to be cathodically controlled, with the metal being more anodically active in the region of the greater percentage of water. The weight loss and solution analysis reveal preferential dissolution of zinc in the initial stages, which decreases progressively with time.