Barrier and self‐healing abilities of corrosion protective polymer coatings and metal powders for aluminum alloys

Several types of coatings, designed to improve the resistance of aluminum alloys to corrosion in seawater, were examined. A coating with a thickness of approximately 30 μm was applied to the surface of aluminum alloy 3003, and after creating an artificial defect by means of a knife‐edge, a corrosion test was carried out in 3% NaCl solution at a temperature of 70°C and pH 1.5. The test results showed that a fluorine resin and sol‐gel coatings both had excellent barrier abilities. The fluorine resin coating had self‐healing abilities, and this was improved by the addition of a metal powder.