Corrosion resistant chromate conversion coatings for heat-treated aluminum alloys

摘要

An improved method of coating 7000 series aluminum alloys, which are difficult to coat uniformly, with a coating resistant to long term corrosion in a salt spray environment is disclosed. By using a chromate solution of very low pH and applying that solution first as a cleaner, followed by brush application to form the final coating, an extended resistance to corrosion at least 2 to 3 times the usual duration is achieved readily.