Atmospheric Corrosion of Aluminum Alloy 6063 Beneath Ferric Chloride Corrosion Product Droplets

Abstract

The atmospheric corrosion behavior of aluminum alloy 6063-T5 with exposure to FeCl3-containing droplet deposits has been investigated using x-ray computed tomography analysis. A voluminous corrosion product cap is formed, with iron oxyhydroxide/oxide deposits forming a coherent layer at the aluminum interface. Exposure to a single droplet is compared with exposure to multiple droplets, and the effect of corrosion product development and FeCl3 concentration on the corrosion rate has been determined. Multiple wet periods with small droplet volumes resulted in higher corrosion rates than comparable single droplet exposures.