Corrosion and passivation behaviors of three brass alloys, including select
ive leaching of the alloys in acidic, neutral, and basic solutions, were in
vestigated in aqueous solutions of different prl, Open-circuit potential me
asurements, polarization data, and electrochemical impedance spectroscopy (
EIS) were used to obtain the corrosion current density, corrosion potential
, and corrosion resistance of each alloy, Results, especially for open-circ
uit potential behavior, were compared to those of the pure alloy constituen
ts (i.e., copper, lead, and zinc), In aqueous solutions, the alloy surface
was covered by a passive Cu(I) film, which was responsible for the passive
behavior of the surface. The stability of such a passive film was dependent
upon the solution pH and was affected by alloy composition The presence of
oxygen (O-2) or oxidizers such as dichromate (Cr2O72-) in the solution or
the increased ratio of active component in the alloy enhanced the dispropor
tionation reactions, which led to breakdown of the passive film. X-ray phot
oelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were us
ed to explain and to confirm polarization and EIS results. A mechanism for
the reactions taking place at the electrode/electrolyte interface was sugge
sted.