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Bogdan Szczygiel - One of the best experts on this subject based on the ideXlab platform.
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the influence of molybdenum on the corrosion resistance of ternary zn co mo alloy coatings deposited from citrate sulphate bath
Corrosion Science, 2015Co-Authors: Juliusz Winiarski, Wlodzimierz Tylus, Katarzyna Winiarska, Bogdan SzczygielAbstract:Abstract Ternary Zn–Co–Mo alloy coatings were deposited from a citrate–sulphate bath. In a pH range of 5.5–5.9 the coatings contained 2.3–3.6 wt.% molybdenum and 3.4–3.7 wt.% cobalt. DC and EIS measurements revealed that in the course of 24 h exposure to NaCl solution the corrosion resistance of Zn–Co–Mo alloy coatings was higher than that of Zn and Zn–Co coatings. On the basis of XRD, ALSV and XPS studies it can be stated that the beneficial effect on the corrosion resistance of Zn–Co–Mo coatings has a Passive Layer composed of: Zn(OH) 2 , ZnO, Mo(IV) oxide and hydroxide and a small amounts of Co 3 O 4 .
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the influence of molybdenum on the corrosion resistance of ternary zn co mo alloy coatings deposited from citrate sulphate bath
Corrosion Science, 2015Co-Authors: Juliusz Winiarski, Wlodzimierz Tylus, Katarzyna Winiarska, Bogdan SzczygielAbstract:Abstract Ternary Zn–Co–Mo alloy coatings were deposited from a citrate–sulphate bath. In a pH range of 5.5–5.9 the coatings contained 2.3–3.6 wt.% molybdenum and 3.4–3.7 wt.% cobalt. DC and EIS measurements revealed that in the course of 24 h exposure to NaCl solution the corrosion resistance of Zn–Co–Mo alloy coatings was higher than that of Zn and Zn–Co coatings. On the basis of XRD, ALSV and XPS studies it can be stated that the beneficial effect on the corrosion resistance of Zn–Co–Mo coatings has a Passive Layer composed of: Zn(OH) 2 , ZnO, Mo(IV) oxide and hydroxide and a small amounts of Co 3 O 4 .
A J Arvia - One of the best experts on this subject based on the ideXlab platform.
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a comparative study on the passivation and localized corrosion of α and β brass in borate buffer solutions containing sodium chloride ii x ray photoelectron and auger electron spectroscopy data
Corrosion Science, 1995Co-Authors: J Morales, P Esparza, G T Fernandez, S Gonzalez, Jose Antonio Espinosa Garcia, J M Caceres, R C Salvarezza, A J ArviaAbstract:The composition of corrosion Layers formed on α-, β- and (α + β)-brass anodized in the Passive region in borate-boric acid buffer and 0.5 M NaCl + borate-boric acid buffer (pH 9) was studied comparatively by X-ray photo-electron and Auger electron spectroscopy. Passivation of brass in both solutions involves the formation of a complex Passive Layer consisting of ZnO and Cu2O. In both solutions, the ZnO electroformation results in a dezincification so that a thin Cu rich Layer is formed at the alloy/metal oxide interface. Passive Layer composition and dezincification of the alloy surface explain the localized corrosion resistance of brass as compared to polycrystalline Cu and Zn.
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a comparative study on the passivation and localized corrosion of α β and α β brass in borate buffer solutions containing sodium chloride i electrochemical data
Corrosion Science, 1995Co-Authors: J Morales, P Esparza, G T Fernandez, S Gonzalez, R C Salvarezza, A J ArviaAbstract:The passivation and localized corrosion of α-, β-, and (α + β)-brass in borate-boric acid buffer solutions (pH 9) containing different NaCl concentrations (cNaCl) were studied comparatively using conventional electrochemical techniques at 25 °C. The passivation of brass in borate-boric acid buffer was due to the electroformation of a complex Passive Layer consisting of ZnO · xH2O and Cu2OCuO. In NaCl-containing borate-boric acid buffer the breakdown of the Passive Layer occurs leading to pitting corrosion when the applied potential exceeds a certain critical value, Eb. For a given type of brass, the value of Eb is shifted negatively as cNaCl is increased. At a constant cNaCl the localized corrosion resistance of brass increases in the following order (α + β)-brass ≅ β-brass < α-brass. For all brass the localized corrosion resistance was lower than that of polycrystalline Cu, but considerably greater than that of polycrystalline Zn. Passive film composition and de-alloying can account for the localized corrosion resistance of these alloys.
Juliusz Winiarski - One of the best experts on this subject based on the ideXlab platform.
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the influence of molybdenum on the corrosion resistance of ternary zn co mo alloy coatings deposited from citrate sulphate bath
Corrosion Science, 2015Co-Authors: Juliusz Winiarski, Wlodzimierz Tylus, Katarzyna Winiarska, Bogdan SzczygielAbstract:Abstract Ternary Zn–Co–Mo alloy coatings were deposited from a citrate–sulphate bath. In a pH range of 5.5–5.9 the coatings contained 2.3–3.6 wt.% molybdenum and 3.4–3.7 wt.% cobalt. DC and EIS measurements revealed that in the course of 24 h exposure to NaCl solution the corrosion resistance of Zn–Co–Mo alloy coatings was higher than that of Zn and Zn–Co coatings. On the basis of XRD, ALSV and XPS studies it can be stated that the beneficial effect on the corrosion resistance of Zn–Co–Mo coatings has a Passive Layer composed of: Zn(OH) 2 , ZnO, Mo(IV) oxide and hydroxide and a small amounts of Co 3 O 4 .
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the influence of molybdenum on the corrosion resistance of ternary zn co mo alloy coatings deposited from citrate sulphate bath
Corrosion Science, 2015Co-Authors: Juliusz Winiarski, Wlodzimierz Tylus, Katarzyna Winiarska, Bogdan SzczygielAbstract:Abstract Ternary Zn–Co–Mo alloy coatings were deposited from a citrate–sulphate bath. In a pH range of 5.5–5.9 the coatings contained 2.3–3.6 wt.% molybdenum and 3.4–3.7 wt.% cobalt. DC and EIS measurements revealed that in the course of 24 h exposure to NaCl solution the corrosion resistance of Zn–Co–Mo alloy coatings was higher than that of Zn and Zn–Co coatings. On the basis of XRD, ALSV and XPS studies it can be stated that the beneficial effect on the corrosion resistance of Zn–Co–Mo coatings has a Passive Layer composed of: Zn(OH) 2 , ZnO, Mo(IV) oxide and hydroxide and a small amounts of Co 3 O 4 .
Francisco Vicente - One of the best experts on this subject based on the ideXlab platform.
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Electrochemical impedance spectroscopy for studying Passive Layers on steel rebars immersed in alkaline solutions simulating concrete pores
Electrochimica Acta, 2007Co-Authors: M. Sánchez, J. Gregori, Cruz Alonso, José Juan García-jareño, Hisasi Takenouti, Francisco VicenteAbstract:Present paper deals with the use of the electrochemical impedance spectroscopy to identify different processes in the Passive Layer growth over steel rebar surface immersed in an alkaline media simulating the concrete pore solution. Two cases have been considered: a Passive Layer spontaneously grown in a high alkaline media and a Passive Layer assisted by the application of an anodic potential in the same media. The application of electric equivalent circuits allows distinguishing between the different mechanisms occurring in this Passive Layer when grows in different conditions. An electric equivalent circuit with two RC loops connected in parallel is often used for fitting the EIS diagrams obtained for spontaneous growth of Passive Layers in the alkaline solution simulating the concrete pores. However, when the Passive Layer is formed under anodic polarization, a Warburg element must be introduced in the equivalent circuit. According to the Point Defect Model (PDM), this Warburg element is allocated to the transport of oxygen vacancies through the Passive Layer, which concentration changes with the potential.
J Morales - One of the best experts on this subject based on the ideXlab platform.
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a comparative study on the passivation and localized corrosion of α and β brass in borate buffer solutions containing sodium chloride ii x ray photoelectron and auger electron spectroscopy data
Corrosion Science, 1995Co-Authors: J Morales, P Esparza, G T Fernandez, S Gonzalez, Jose Antonio Espinosa Garcia, J M Caceres, R C Salvarezza, A J ArviaAbstract:The composition of corrosion Layers formed on α-, β- and (α + β)-brass anodized in the Passive region in borate-boric acid buffer and 0.5 M NaCl + borate-boric acid buffer (pH 9) was studied comparatively by X-ray photo-electron and Auger electron spectroscopy. Passivation of brass in both solutions involves the formation of a complex Passive Layer consisting of ZnO and Cu2O. In both solutions, the ZnO electroformation results in a dezincification so that a thin Cu rich Layer is formed at the alloy/metal oxide interface. Passive Layer composition and dezincification of the alloy surface explain the localized corrosion resistance of brass as compared to polycrystalline Cu and Zn.
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a comparative study on the passivation and localized corrosion of α β and α β brass in borate buffer solutions containing sodium chloride i electrochemical data
Corrosion Science, 1995Co-Authors: J Morales, P Esparza, G T Fernandez, S Gonzalez, R C Salvarezza, A J ArviaAbstract:The passivation and localized corrosion of α-, β-, and (α + β)-brass in borate-boric acid buffer solutions (pH 9) containing different NaCl concentrations (cNaCl) were studied comparatively using conventional electrochemical techniques at 25 °C. The passivation of brass in borate-boric acid buffer was due to the electroformation of a complex Passive Layer consisting of ZnO · xH2O and Cu2OCuO. In NaCl-containing borate-boric acid buffer the breakdown of the Passive Layer occurs leading to pitting corrosion when the applied potential exceeds a certain critical value, Eb. For a given type of brass, the value of Eb is shifted negatively as cNaCl is increased. At a constant cNaCl the localized corrosion resistance of brass increases in the following order (α + β)-brass ≅ β-brass < α-brass. For all brass the localized corrosion resistance was lower than that of polycrystalline Cu, but considerably greater than that of polycrystalline Zn. Passive film composition and de-alloying can account for the localized corrosion resistance of these alloys.
