Abstract
Corrosion of test assets and other structures used by the Missile Defense Agency (MDA) and other DOD branches is an ongoing maintenance and reliability issue. The tropical marine environment, such as the Marshall Islands or the Hawaiian Islands, is highly corrosive and improved corrosion protection and control (CPC) methods are needed to protect valuable and critical assets and infrastructure. A solution to this corrosion problem is smart appliqués that provide excellent corrosion protection and health monitoring to alert an inspector if the appliqué has been damaged or has deteriorated. These smart appliqués are peel-and-stick fluoropolymer films with a sensor electrode and pressure sensitive adhesive. Aluminum and steel panels with smart appliqués were exposed to 2000 hours of salt fog. No corrosion was observed on any of the defect-free specimens. On the scribed aluminum panels, no undercutting of the appliqué was seen at the scribe except when a copper electrode induced galvanic attack. On the scribed steel panels, undercutting did not exceed 1-2 mm. Electrochemical impedance spectroscopy (EIS) measurements using the embedded sensors allowed health monitoring. The sensors easily detected the early stages of corrosion resulting from a scribe in the appliqué and from a backside defect. For the backside defects, the sensor measurements correlated with the amount of corrosion present. These sensors would easily detect any damage to the appliqué or poor appliqué installation before any damage to the structure occurred.
