Anodic electrochemical dissolution of metals is often used in commercial electropolishing, and the copper/phosphoric acid system is a classic example. Surface films are believed essential for polishing, but their composition and role remain elusive. Current oscillations, which may be excited, have been attributed to film formation and breakdown. This study examines the information obtained from voltammetric measurements using rotating disk electrodes. Steady‐state currents are limited by a diffusion process whose rate is dependent only upon the solution viscosity and is otherwise independent of its composition. Our results indicate a key role for water and suggest that the film may be a highly viscous, dehydrated surface layer. The oscillations are due to negative impedance surface characteristics.
No takes yet. Share an insight, caveat, or question.
Glarum et al. (1985) studied this question.