SURFACE-TOLERANT, ALUMINUM-FOIL, TAPE COATING

摘要

Aluminum foil coatings are applied by adhering a laminated film containing an aluminumrnfoil layer to a steel substrate. Aluminum foil coatings are known to possess better barrier propertiesrnand provide better protection to corners (sharp edges) than conventional liquid applied coatings ofrnsimilar film thickness. A cyclic salt-fog test was used to characterize the corrosion control behaviorrnof various aluminum foil coatings applied to rusted steel. The test data showed that, in addition torncontrolling corrosion by a barrier mechanism, some of the foil coatings controlled the spread ofrncorrosion at scribes and holidays by a cathodic protection mechanism. Rust creepage rate decreasedrnas foil thickness increased. Most of the foil coatings outperformed the epoxy mastic coating that wasrnused as a comparison. Adhering bare foil directly to a minimally prepared, rusted steel substraternresulted in rapid pitting and perforation of the foil; however pitting did not occur if an intermediaternorganic layer was present, between the foil and the rusted steel. In the maintenance of minimallyrnprepared steel in a marine atmosphere, a properly designed coating system, containing an aluminumrnfoil layer, would be expected to be significantly more durable than a traditional liquid appliedrncoating of similar film thickness.