Corrosion Rate Of Copper Research Articles

Inhibition de la corrosion du cuivre en milieu HCl 0,5 M par les composes organiques de type triazole

Some triazole-type organic compounds were tested as corrosion inhibitors for copper in 0.5 M HCl solution at 20°C. Electrochemical (potentiodynamic polarization and polarization resistance measurements) and gravimetric methods were used for this study. The obtained results showed that 3-amino-1,2,4 triazole (ATA) and 3,5 diamino-1,2,4 triazole (DTA) effectively reduce the corrosion rate of copper. The inhibition efficiency (E%) of these compounds increases with their concentrations and attains maximum values at 10 −3M and 10 −4 for ATA and DTA, respectively. The variation of efficiency with logC shows that these inhibitors are adsorbed on the metallic surface according to the Frumkin adsorption isotherm model.

Copper corrosion by-product release in long-term stagnation experiments

The effect of long-term stagnation on copper corrosion by-product release and corrosion rates was studied in pipe-rigs according to the German standard DIN 50931, Part 1. The analysis of the water phase was supplemented by surface analysis of corrosion scales. Copper concentration during stagnation did not follow a solubility process. The characteristic curves obtained can be explained by subsequent copper release and copper refixation processes. Oxygen consumption can be described by the first-order kinetic rate law. The corrosion scales consisted of cuprite (Cu2O) and malachite (CuCO3·Cu(OH)2). Malachite grew in well-defined crystals during stagnation, served as sink for dissolved copper and did not protect the pipe against corrosion attack. Copper concentrations measured after long-term stagnation (up to 122h) correspond to the solubility of malachite in the testwater.

Effect of phosphate ions on electrochemical behaviour of copper in sulphate solutions

Abstract The effect of phosphate ions on the corrosion behaviour of copper in sulphate solutions was investigated at different temperatures (293, 313, 333, and 353 K) and at different pH values (pH = 2·1, 7·2, and 12·3). A three electrode electrochemical technique was used for the measurements, using a saturated calomel electrode (SCE) for reference purposes. Both anodic and cathodic polarisation curves were established, from which the anodic and cathodic Tafel constants were determined. Corrosion potentials were determined by extra trapolation of the anodic and cathodic Tafel lines to the point of zero current density. The results showed that for a pH value of 2·1, the corrosion rate of copper showed a marked tendency to increase with increasing temperature in solutions containing either sulphate alone or sulphate plus phosphate. However, at pH values of 7·2 and 12·3, this tendency became less pronounced in solutions containing sulphate alone and in solutions containing sulphate plus phosphate together, ...

Electrochemical behavior of copper chemical mechanical polishing in KIO[sub 3] slurry

The electrochemical behavior of polishing copper with colloidal silica abrasive slurry formulated with KIO3 oxidizer has been investigated. For planarization of the surface morphology, the control of the surface passivation of Cu is critical during polishing. KIO3 is not only an oxidizer but also a passivator for copper in an acidic slurry by forming a CuI layer on the surface. With alkaline slurry, Cu2O is the primary corrosion product on the Cu surface. The copper corrosion rate and removal rate can be decreased dramatically with increasing slurry pH. The low corrosion resistance or high corrosion susceptibility of Cu as determined by electrochemical measurements is the basis for the high removal rates. The copper removal rate is reduced from 4600 to 650 A/min when the slurry pH is increased from 2 to 5; and the copper removal rate levels off at pH 7 with a steady-state removal rate of 200 A/min.

銅の腐食速度に及ぼす上水中の溶解成分の影響

銅の腐食速度に及ぼす上水中の溶解成分の影響

Study of the Effect of Acetic Acid Vapor on Copper Corrosion at 40 and 80% Relative Humidity

Copper corrosion rate and corrosion products originating from acetic acid vapors have been studied using gravimetric, scanning electron microscopy, X-ray photoelectron spectroscopy, and argon-ion sputtering techniques. Copper specimens were exposed to the action of 10, 100, and 300 ppm acetic acid vapors generated in laboratory experiments at 40 and 80% relative humidity (RH) for a period of 21 days and at 30°C. The copper corrosion rate was in the range from 0.08 to 0.17 (mdd) for 40% RH and from 0.11 to 6.53 mdd for 80% RH. The main compounds found were cuprite copper hydroxide and copper acetate A corrosion process model is proposed in which copper acetate is formed from copper hydroxide present on the copper surface. © 2001 The Electrochemical Society. All rights reserved.

Seasonal variations in corrosion rate and runoff rate of copper roofs in an urban and a rural atmospheric environment

This paper summarizes the results from an extensive field exposure program implemented to study possible seasonal dependencies of copper corrosion rates and runoff rates. Two-year exposures in one urban and one rural environment were performed at four different starting seasons. An extensive multi-analytical approach was undertaken of all exposed samples. Seasonal differences in corrosion product formation was observed during the first month of exposure and attributed mainly to differences in relative humidity conditions. Seasonal differences in corrosion rate at the rural site could be discerned throughout the whole two-year exposure, again, mainly attributed to differences in relative humidity. No seasonal effect could be observed at the urban site indicating that other parameters influenced the corrosion kinetics at this site. While corrosion rates exhibit a continuous decrease with exposure time, the yearly runoff rates are independent of time. Depending on starting months the yearly copper runoff rates ranged from 1.1 to 1.7 g m −2 y −1 for the urban site, and from 0.6 to 1.0 g m −2 y −1 for the rural site. These seasonal variations were primarily attributed to differences in precipitation quantity and environmental characteristics. Runoff rates are significantly lower than corrosion rates as long as the adhering copper patina is growing with exposure time. A full risk assessment requires not only information on the total amount of copper in the runoff, but also on its chemical speciation. Under present conditions, 70–90% of all copper in runoff water collected immediately after leaving the surface is present as the most bioavailable form, the hydrated cupric ion, Cu(H 2O) 6 2+.

Water treatment to reduce internal corrosion in the drinking water distribution system in Oslo

In 1995 the new Skullerud water treatment plant was put into operation. The new water treatment includes colour removal and corrosion control with an increase of pH, alkalinity and calcium concentration in addition to the old treatment, which included straining and chlorination only. Comparative measurements of internal corrosion were conducted before and after the installation of the new treatment plant. The effect of the new water treatment on the internal corrosion was approximately a 20% reduction in iron corrosion and a 70% reduction in copper corrosion. The heavy metals content in standing water was reduced by approximately 90%. A separate internal corrosion monitoring programme was conducted, studying the effects of other water qualities on the internal corrosion rate. Corrosion coupons were exposed to the different water qualities for nine months. The results showed that the best protection of iron was achieved with water supersaturated with calcium carbonate. Neither a high content of free carbon dioxide or the use of the corrosion inhibitor sodium silicate significantly reduced the iron corrosion rate compared to the present treated water quality. The copper corrosion rate was mainly related to the pH in the water.

A comparative study on copper corrosion originated by formic and acetic acid vapours

The copper corrosion rate and products originated by the action of formic and acetic acid vapours at a 100% relative humidity were studied. Copper specimens were exposed to formic and acetic acid vapours for a period of 21 days. Five formic and acetic acid vapour concentrations (10, 50, 100, 200 and 300 ppm) were tested. Copper corrosion rates of up to 1300 mg m−2 d−1 (mmd) for formic acid and up to 2300 mmd for acetic acid were measured using a gravimetric method. The corrosion-product layers were characterised using electrochemical, X-ray powder diffraction and scanning electron microscopy techniques. Some of the compounds identified were: cuprite (Cu2O), for both acids; cupric hydroxide monohydrate (Cu(OH)2 · H2O) and copper formate tetrahydrate (Cu(HCOO)2 · 4H2O), for formic acid; and copper acetate dihydrate (Cu(CH3COO)2 · 2H2O) and copper hydroxide acetate dihydrate (Cu4(OH)(CH3COO)7 · 2H2O), for acetic acid.

The effect of adatoms on the corrosion rate of copper

On the premises that corrosion is a surface process and adatoms modify the electronic states of the surface, the influence of Zn, Sn, S, I, F, Ta, Sb, Ti, Bi and Cr adatoms on the corrosion rate of copper was investigated. Adatoms were adsorbed at open-circuit from a solution containing 1.0×10 −2 mol l −1 of the ions of the adatom element. The coverage of the adatoms at the surface was calculated by integration of the area under one of the peaks on the voltammogram of the copper electrode before and after dosing the electrode with the adatom. A significant difference in adsorbability of the adatoms at copper surface was observed. This difference was inter alia attributed to atomic size, crystallographic and kinetic effects. The surface properties were characterized by cyclic voltammetry, and for selected systems by SEM and electron microprobe. Corrosion of the surface in presence and in absence of the adatoms was followed by weight-loss method while surface oxidation, ‘surface corrosion’ was investigated by cyclic voltammetry and by electrochemical polarization techniques. The results showed that the nonmetals (F, S and I) markedly enhanced the rate of corrosion; Cr, Ta, Sb, Bi, Ti, Sn slightly enhanced the rate of corrosion of copper. Zinc, however, was the only element which decreased the rate of corrosion.

The influence of oxide layers on initial corrosion behavior of copper in air containing water vapor and sulfur dioxide

To investigate the influence of a surface state on corrosion rates of copper, different surface states of specimens were prepared by different surface finishing methods, and the surfaces under corrosion test in air containing water vapor of 78–83% RH and SO 2 of 16–23 ppm were investigated by in situ IR-RAS. The corrosion rates, especially in the early stage, considerably change depending on the characteristics of the oxide layers: a freshly formed oxide layer with low crystallinity shows a weak inhibition for corrosion, but oxide formed in one day maintains an inhibitive effect for a long time and keeps the corrosion rate very low.

Copper Corrosion Mechanism in the Presence of Formic Acid Vapor for Short Exposure Times

The rate of copper corrosion originated by the action of formic acid vapors at 100% relative humidity was studied. Five formic vapor concentration levels (10, 50, 100, 200, and 300 ppm) were used. A copper corrosion rate of up to was measured for a period of 21 days using a gravimetric method. The patina layers were characterized using cathodic reduction, X‐ray powder diffraction, Fourier transform infrared spectrometry, and scanning electron microscopy techniques. Some of the components identified in the corrosion‐product layers were cuprite , cupric hydroxide hydrate , and copper formate hydrate . The latter was formed by both cupric hydroxide and formic acid‐cuprous ion complex mechanisms. © 2000 The Electrochemical Society. All rights reserved.

Comparison of polarization curve—and electrochemical quartz crystal microbalance methods for determination of copper corrosion rate

The two methods of determining corrosion rate of copper in different media, polarization curve (PC) and electrochemical quartz crystal microbalance (EQCM), has been compared. The polarization curve method based on Gauss–Newton non-linear fitting was applied to estimate corrosion rate and other electrochemical parameters in the low polarization region. The frequency shift of EQCM during the corrosion process was simultaneously recorded during the polarization process and directly related to the mass change of the copper electrode. The results of electrodeposited copper from these two methods in the solutions with different inhibitors were also compared. It was obvious that the presence of inhibitors including benzotriazole and benzoic acid influenced corrosion rate and other electrochemical parameters. It was found that EQCM was a promising technique in determining corrosion rate for its fast, efficient and reliable operation.

Corrosion inhibition of copper by heterocyclic compounds

The corrosion inhibition of copper in aerated 0.5 M H 2SO 4 solution in presence of two classes of heterocyclic compounds, namely phenylazo-pyrazolones (PAP) or hydroxy quinoline and bromobenzyl-carboxy-1,2,3 triazole (BCT) derivatives was studied. The corrosion parameters were obtained at different inhibitor concentrations and the temperature effect was also investigated. The corrosion rate of copper was determined; using Tafel method and the polarization resistance ( R p) technique. The electrolyte solution was analysed using cyclic voltammetry and UV-visible spectroscopy. The results were compared with that of some prepared Cu-complexes in order to explain the inhibition mechanism. Moreover, the thermodynamic activation parameters of the Cu-corrosion reaction were calculated and discussed in relation to the stability of the protective layer. The inhibition effect was attributed to the adsorption of the dye molecules, the precipitation of Cu-chelates and/or formation of π-complexes at the electrode surface.

Influence of the alkyl chain on the protective effects of 1,2,3-benzotriazole towards copper corrosion.: Part I: inhibition of the anodic and cathodic reactions

1,2,3-Benzotriazole (BTAH) and some of its 5-alkyl-derivatives (methyl-, butyl-, hexyl-, octyl-, dodecyl-) were tested by using different electrochemical techniques in order to investigate the influence exerted by the aliphatic chain length on the inhibiting action of the base molecule towards OFHC copper corrosion in acidic sulphate and saline solutions. The polarization curves, recorded after a 3 h immersion in acidic sulphate solution, showed that: • more than 1 μmole l -1 of the additives had to be in the solution to reduce the copper corrosion rate; • the BTAH inhibiting e.ciency increased with the length of the side alkyl chain up to six carbon atoms; • chiefly, the action of the anodic inhibitor of the base molecule is strengthened. The hexyl derivative also exhibited a good e.cacy in acidic chloride solution. 1999 Elsevier Science Ltd. All rights reserved.

Characteristics of copper corrosion in simulated uterine fluid in the presence of protein.

In order to acquire more knowledge of the performance of copper-bearing intrauterine devices (Cu-IUDs), corrosion behavior of copper in a simulated uterine fluid was investigated in the presence of proteins. The proteins studied included serum albumin, gamma-globulin and hemoglobin. Electrochemical polarization resistance measurements indicated that, in all cases under study, the corrosion rate of copper declined with time and the proteins always increased the rate. Moreover, different kinds of protein showed different dependence of copper corrosion rate on protein level. Addition of serum albumin initially raised the copper corrosion rate; however, the higher albumin concentration resulted in less promotion of the corrosion. X-ray diffraction (XRD) of the specimen surface showed that, both in the presence and absence of serum albumin, cuprous oxide was the only corrosion product, even though at higher concentrations of albumin less cuprous oxide was formed. This implies that serum albumin does not alter the corrosion mechanism. Electrochemical cathodic reduction of the oxide film and chemical analysis of solution after corrosion testing proved that the proportion of soluble ionic copper in the whole corrosion products varied with the albumin level. The copper corrosion rate in the presence of gamma-globulin or hemoglobin increased monotonically with increasing concentration of the protein. These three proteins shifted the corrosion potential of copper towards negative. It could be inferred that the proteins accelerated the anodic dissolution process of copper and hence enhanced its corrosion.

A Modeling Study of General Corrosion of Copper Overpack for Geological Isolation of High-Level Radioactive Waste

AbstractThis paper describes a modeling study for general corrosion of copper which is a candidate material for high-level radioactive waste overpacks. The model is a mixed-potential model combined with diffusive transport of reactants and reaction products. The rest potential and corrosion rate of copper in aerated solution were measured while controlling the thickness of a diffusive solution layer on the copper surface using a rotating-disk electrode. Experimental data were used for validation of the model.

A Laboratory Study of the Effect of Acetic Acid Vapor on Atmospheric Copper Corrosion

A study was made of the copper corrosion rate and corrosion products originated by the action of acetic acid vapor at 100% relative humidity. Copper plates were exposed to an acetic acid contaminated atmosphere for a period of 21 days. Five acetic vapor concentration levels were used. The copper corrosion rate was in the range of 1 to 23 mg/dm2 day. The corrosion‐product layers were characterized using electrochemical, X‐ray powder diffraction, Fourier transform infrared spectrometry, and scanning electron microscopy techniques. Thermal and calorimetric studies were also performed. Some of the compounds identified were cuprite , copper acetate hydrate , and copper hydroxide acetate . This last compound was also characterized. The thickness of the patina layers was 4 to 8 nm for amorphous cuprite, 11 to 48 nm for cuprite, and 225 nm for copper acetate. The patina, in which the cementation process of different corrosion‐product layers plays an important role, is formed by the reaction of acetic vapor with copper through porous cuprite paths.

Corrosion Behavior of Copper in a Copper Bearing Intrauterine Device in the Presence of Indomethacin

As an improvement to the use of the copper bearing intrauterine device, indomethacin has been introduced to reduce the incidence of bleeding after insertion of the device. The effects of indomethacin on copper corrosion were studied in vitro in simulated uterine fluid. Electrochemical polarization resistance measurements indicated that indomethacin powder slightly increased the corrosion rate of copper if pH of the fluid was not under control and it did not change the corrosion rate if pH was adjusted daily to maintain some constancy. The experimental results for medication by indomethacin-releasing Silastic® were basically the same as those with powdered indomethacin. X-ray diffraction showed that only cuprous oxide was formed on the copper substrated surface and that indomethacin did not affect the corrosion products. As scanning electron microscopy demonstrated, however, in the presence of indomethacin the oxide particles formed were found to be more coarse and dense than in the absence of indomethacin.

Investigation on copper corrosion behaviour in industrial waters by electrochemical noise analysis

This paper represents an attempt to apply electrochemical noise analysis to monitor copper corrosion rates in solutions simulating near neutral or acidic industrial waters, containing chloride, sulphate and bicarbonate ions. The very low noise levels characterizing these systems make the evaluation of the noise resistance possible only with a four electrode arrangement, where the electrode couples used to detect the voltage and current fluctuations have different surface areas. This arrangement is probably a handicap to the evaluation of the polarization resistance values from noise resistance data. Cyclic voltammetries were carried out in order to investigate the nature of the corrosion products obtained in solutions with different pH.