This research examines the effectiveness of six non-chromate conversion coatings on aluminum armor alloys 5083,7039 and 2519. Evaluation included salt fog, cyclic salt spray, wet adhesion, and electrochemical impedance spectroscopy on both painted and unpainted test panels. Large differences in behavior were noted between the salt fog data obtained on unpainted panels and the cyclic salt spray data obtained on painted and scribed panels. How this data will affect the implementation of non-chromate pretreatment within the US Army is discussed. Additionally, these findings provide guidance for continued development of non-chromate conversion coatings and their eventual performance standards.
Keywords: non-chromate, chromate, aluminum, armor, impedance, salt fog, cyclic salt spray