Abstract: The influence of wire radius (0.04-0.82 mm) on the corrosion behavior of copper wires was investigated in naturally aerated 0.5 mol·L-1 NaCl solution (pH=7.4), by means of polarization and electrochemical impedance spectroscopy method. The results showed that the mass transfer process was significantly accelerated by non-linear diffusion when radius of copper wire was less than the thickness of diffusion layer (0.56 mm), and consequently, the cathodic and anodic reaction rates controlled by diffusion, as well as the corrosion current density, increased rapidly. It showed that the influence was accelerated with the decrease of wire radius. By comparing cathodic oxygen reduction reaction of platinum and stainless steel wires, the same results were obtained. Therefore, the size effect on corrosion behavior of copper wires is a widespread phenomenon.

Key words: Copper, Wire electrode, Corrosion, Non-linear diffusion, Size effect