Electrochemical study of the corrosion behavior of bronze under acetic acid-containing thin electrolyte layers

Abstract

The corrosion behavior of bare bronze, bronze with Cu2O patina and bronze with CuCl patina under acetic acid-containing thin electrolyte layers (TELs) with various thickness was studied by electrochemical tests, SEM-EDS and XRD analysis. The results indicated that the corrosion rate of these three bronze samples under different TEL thicknesses is lower than that in bulk solutions. Besides, the corrosion rate of bare bronze increases as TEL thickness increases, and as for the bronze with Cu2O patina or bronze with CuCl patina, the critical thickness is about 198 μm or 152 μm. Moreover, the Cu2O patina layer can protect the bronze matrix, while the CuCl patina layer will accelerate the corrosion process. The major corrosion products of bare bronze and bronze with Cu2O patina in the acetic acid vapor are Cu2O and hydrate of copper acetate, but for bronze with CuCl patina, the corrosion products on the surface is mainly Cu2Cl(OH)3.