الفهرس 
Copper and Its AlloysOnly 14 pages are availabe for public view
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Abstract
A survey is given which summarises the pervious studies on the electrode behaviour and corrosion phenomena associated with copper and copper alloy, the behaviour of copper and copper alloy was studied in 3 M nitric acid solution free and containing different inhibitor concentrations.
Different techniques were applied to study the effect of the inhibitors butanediamine (BDA), ethylenediamine (EDA) and ethylamine (EA) on the corrosion behaviour of copper and copper alloy in 3 M nitric acid solution. . . The first technique, involved the direct determination of the corrosion rate from the loss in weight of copper and copper alloy sheets immersed in 3M nitric acid solution free and containing different inhibitors concentrations were studied in the temperature range 30-60°C.
The second technique is the study of the potential of copper and copper alloy electrode in 3M nitric acid solution free and contaning different inhibitor concentrations at 30°C.
The third technique, potentiodynamic polarization curves of copper and copper alloy in 3M nitric acid in the absence and in the presence of the different organic compounds under investigation.
The fourth technique is SEM measurements. The morphological surface picture of copper and copper alloy after 1 hour dipping in 3M nitric acid solution free at 30°C.and with 1% of BDA, EDA or EA. . KK KKKKKKKKKKKKKKKKKKKKK
The individual tasks undertaken and the conclusions arrived can be classified into the following:
1) The corrosion rate decreases with increasing the inhibitor concentrations.
2) The protection efficiency increases with the increase of the inhibitor concentrations at constant temperatures.
3) The protection efficiency increases appreciably with decreasing the temperature. . This means that the inhibitive action of these substances results from the physical adsorption. The weight loss of copper and copper alloy were studied also at different temperatures in the temperature range 30-60°C. . 4) The protection efficiency of copper alloy was higher than that of copper due to the presence of nickel.
5) The calculated equilibrium constant k of the adsorption reaction for copper is 2750, 1100.1 and 613.4 Lmol-1 which lead to ∆G°= -30.017, -27.713 and -26.243 KJmol-1 in BDA, EDA and EA, respectively. And the calculated equilibrium constant k of the adsorption reaction for copper alloy is 2000, 1000 and 546.4 Lmol-1 which lead to ∆G°=-29.216, -27.473and -25.953 in BDA, EDA and EA, respectively.The negative value of the standard free energy of adsorption indicates that spontaneous adsorption of these inhibitors on copper and copper alloy take place.
6) The potential of copper and copper alloy was measured at 30 °C within a period of 2 hours until constant potential is reached in the absence and in the presence of the different inhibitors concentrations varying between 0.001-1M.
7) The plot of the steady state potential of copper and copper alloy against logarithm of free acid containing different inhibitors concentrations indicated the decrease of the corrosion potential with increase of the inhibitors concentration.
8) Cathodic current potential curves give rise to parallel Tafel lines indicating that the hydrogen evolution reaction is activation controlled and the addition of the studied inhibitors does not modify the mechanism of this process.
9) The adsorbed molecules of studied compounds have no effect on the mechanism of either copper or copper alloy dissolution or (hydrogen evolution reaction).
10) The value of corrosion potential (Ecorr) is modified by the addition of compounds studied.
11) The addition of compound studied decreases the current densities in a large domain of anodic and cathodic potentials.
12) It is clear that the corrosion attack was more pronounced in absence of additives, while by the addition of different inhibitors the film formed on copper and copper alloy surface become more protective.
13) The protective film is more pronounced for BDA, EDA then EA.
The general conclusion is that all inhibitors used are excellent inhibitors for protecting for copper and copper alloy in nitric acid. The sequence of the different inhibitor for protected copper and copper alloy is BDA>EDA>EA.