THE KINETICS OF PITTING CORROSION OF COPPER IN ALKALINE-SOLUTIONS CONTAINING SODIUM-PERCHLORATE

The pitting corrosion of Cu has been investigated in 0.1 M NaClO4, 8-11 pH range, through voltammetry and potentiostatic transient techniques complemented with scanning electron microscopy observations. Phenomenological relationships between breakdown potential, density of pits, spatial pit distribution, pH and applied potential have been established. Results are interpreted in terms of a nucleation and growth mechanism under two different kinetic controls. The transition in the rate controlling process depends on the extent of the pitting process. The spatial distribution of pits suggests the random nature of pit nucleation on the Cu surface.