Articulo
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
Autor
Morales, Jose Carlos
Esparza, Pedro
Fernández, Guillermina T.
González, Sergio G.
García, J. E.
Cáceres, J. M.
Salvarezza, Roberto Carlos
Arvia, Alejandro Jorge
Institución
Resumen
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 Cu<sub>2</sub>O. 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. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas Facultad de Ciencias Exactas