VALCARCE Maria beatriz
Surface characterization of copper, zinc and brass in contact with tap water inhibited with phosphate ions
YOHAI L.; VAZQUEZ M.; W. SCHREINER; M.B. VALCARCE
APPLIED SURFACE SCIENCE
ELSEVIER SCIENCE BV
Lugar: Amsterdam; Año: 2011 vol. 257 p. 10089 - 10095
The composition of the surface layers has been investigated on copper, zinc and brass in contact withmoderately hard, highly carbonated and chloride rich artificial tap water (ATW). Cyclic voltammetry,reflectance spectroscopy, X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopyhave been used to identify the changes in composition that result from the incorporation of sodiumorthophosphate to ATW. The results showed that when PO43− is added, the film changes its compositionand it also becomes thinner, denser and more compact. On copper, the presence of CuO in the passivefilm can be correlated to the improvement in the corrosion behavior in the presence of phosphate ions.In the case of brass, the development of a thinner, compact and less porous Zn3(PO4)2 layer hindersCu(I) dissolution. A mechanism explaining the effect of this inhibitor is proposed, which accounts for theexperimental results.