GM 9540P Cyclic Accelerated Corrosion Analysis of Nonchromate Conversion Coatings on Aluminum Alloys 2024, 2219, 5083, and 7075 Using DOD Paint Systems

摘要

This study examines corrosion resistance of eight nonchromate conversion coatings versus hexavalent chromium based Alodine 1200 controls on scribed coated test panels of aluminum alloys 2024, 2219, 5083, and 7075. Five representative DOD primer/topcoat organic coating systems were evaluated for each of the conversion coating/alloy combinations. Scribed panels were exposed using GM 9540P for 120 cycles duration and were photographed and measured at 20 cycle intermediate intervals for scribe creepback using method ASTM D 1654. Differences in pretreatment performance based upon variation in coating type as well as alloy were noted. How these data may relate with respect to implementation of nonchromate pretreatments for different military applications is discussed.