Digital Holographic Study of pH Effects on Anodic Dissolution of Copper in Aqueous Chloride Electrolytes

Abstract

The anodic dissolution of copper in chloride electrolytes with different pH has been investigated by using polarization measurements and digital holography. In acidic and neutral NaCl solutions, the oxidation processes of copper are almost the same: copper firstly dissolves as cuprous ions, which then produces the CuCl salt layer. The dissolution rate in the acidic solution is a little higher than that in the neutral. However, the mechanism is quite different in the alkaline NaCl solution: copper turns passive easily due to the formation of a relatively stable Cu 2 O film which results in pitting, and the dissolution rate of copper decreases before pit initiation.

Investigation of the corrosion behavior of aluminum bronze alloy in alkaline environment

“…The excessive release of copper ions with increase in alkalinity is due to surface interactions and has been reported by many researchers [27–29]. The increase in the rate of dissolution of copper ions into solution is due to the removal of the protective layer of aluminum oxide on the surface of aluminum bronze alloy with increasing alkalinity of the solution [30]. According to the inductively coupled plasma results, the observed changes in the concentrations of the elements at pH values of 8.5 and 9.5 are not significant.…”