Current and Potential Distributions in Plating Corrosion Systems

The numerical determination of current and potential distributions has been performed for plating corrosion systems, where failure to coat a small area leads to corrosion at the pinhole. The distributions depend on characteristic parameters for the disk anode and surrounding plane cathode and reveal that each of the electrodes influences the other due to their proximity. The results were applied to an array of disks, and it was found that the corrosion potential of the system is a linear function of the area ratio of anode to cathode when ohmic effects are important. This may be contrasted to the logarithmic dependence found when ohmic effects are neglected. Other applications are discussed.