Chrome-Free Coatings to Combat Corrosion in Sensitized 5xxx Aluminum Alloys

摘要

1. Traditional zinc primers are very effective at combating SCO of sensitized AA5083-H116 a. Our work validates concept of using galvanic protective coatings (zinc) to drop alloy potential to passive region 2. Luna's non-chrome inhibitors (both organic and inorganic) demonstrated improvement over traditional COTS non-chrome coating system 3. While zinc coatings may seem like "silver bullet" for sensitized AA5XXX alloys, coatings are heavy and may not be acceptable on certain platforms a. Common zinc coatings → -12-13 g/sq.ft. b. Luna coatings → -4 g/sq.ft.