Investigation of the Influence of Applied Potential on Erosion-Corrosion ofCopper in Alkaline Chloride Solutions

摘要

A novel electrochemical cell incorporating a scanning ellipsometer was designedand used to investigate the hypothesis that the critical shear observed for the erosion-corrosion of copper was associated with a shear-induced removal of protective film. While high-shear flow was shown to increase the rate of corrosion of copper in aerated and de-aerated saline solutions, ellipsometry indicated that shear induced removal of protective films did not take place, even for shear stresses ten times the reported critical shear for erosion-corrosion of copper. Subsequent work showed that a differential mass transfer mechanism could generate localized corrosion, but the visual appearance of the surface did not resemble classical products of erosion-corrosion. Separate potentiodynamic and impedance experiments were conducted to identify the electrochemical behavior, and new techniques were developed to interpret impedance spectra. Papers resulting from this work are attached.