Size distribution of etch pits in aluminum

Abstract Cubic corrosion pits were produced in 99.99% aluminum foil in 1 N HCl electrolyte at temperatures of 3–40°C. Size distribution measurements made on photomicrographs of the pits showed that the width range decreased with temperature. A model based on death of pits by passivation by means of water permeating barrier-layer AlCl 3 films on the pit walls is in apparent agreement with the measurements.