Documents disponibles écrits par cet auteur

Electrochemical behavior of some copper alloys in sulfuric acid solutions / H. E. El-Feky in Materials and corrosion, Vol. 61 N° 7 (Juillet 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 7 (Juillet 2010) . - pp. 599–610 Titre : Electrochemical behavior of some copper alloys in sulfuric acid solutions Type de document : texte imprimé Auteurs : H. E. El-Feky, Auteur ; N. H. Helal, Auteur ; M. R. Negem, Auteur Année de publication : 2010 Article en page(s) : pp. 599–610 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : copper  alloys;  corrosion;  impedance;  potentiodynamic  polarization Résumé : In this article, the corrosion behavior of CuFe and CuAlFe was studied in H2SO4 solutions in the absence and presence of different concentrations of some inorganic additives, Na2MoO4, K2Cr2O7, KIO3, and Na2B4O7. The techniques of measurements used were open-circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy. The polarization measurements indicated that the corrosion current, Icorr, of CuFe is less than that of CuAlFe. The investigated additives in H2SO4 shifted Ecorr to more positive values and increases Icorr. Impedance measurements indicated that Nyquist plots for CuFe may be regarded as a semi-circle in early stages of immersion and tends to be a part of semi-circle with elapse of time and a well-defined inductive loop appears. In case of CuAlFe, the Nyquist plots tends to be semi-circle or depressed semi-circle. The values of Rp for CuFe are higher than those for CuAlFe. On the other hand, the values of Cdl for CuFe are lower than those obtained for CuAlFe. The presence of these additives in H2SO4 solutions decreases the values of polarization resistance (Rp) and increases the values of corrosion current density (Icorr) and capacitance of double layer (Cdl). En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905345/abstract [article] Electrochemical behavior of some copper alloys in sulfuric acid solutions [texte imprimé] / H. E. El-Feky, Auteur ; N. H. Helal, Auteur ; M. R. Negem, Auteur . - 2010 . - pp. 599–610. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 7 (Juillet 2010) . - pp. 599–610 Mots-clés : copper  alloys;  corrosion;  impedance;  potentiodynamic  polarization Résumé : In this article, the corrosion behavior of CuFe and CuAlFe was studied in H2SO4 solutions in the absence and presence of different concentrations of some inorganic additives, Na2MoO4, K2Cr2O7, KIO3, and Na2B4O7. The techniques of measurements used were open-circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy. The polarization measurements indicated that the corrosion current, Icorr, of CuFe is less than that of CuAlFe. The investigated additives in H2SO4 shifted Ecorr to more positive values and increases Icorr. Impedance measurements indicated that Nyquist plots for CuFe may be regarded as a semi-circle in early stages of immersion and tends to be a part of semi-circle with elapse of time and a well-defined inductive loop appears. In case of CuAlFe, the Nyquist plots tends to be semi-circle or depressed semi-circle. The values of Rp for CuFe are higher than those for CuAlFe. On the other hand, the values of Cdl for CuFe are lower than those obtained for CuAlFe. The presence of these additives in H2SO4 solutions decreases the values of polarization resistance (Rp) and increases the values of corrosion current density (Icorr) and capacitance of double layer (Cdl). En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905345/abstract