Extended Performance Assessment in Accelerated Corrosion and Adhesion of CARC Prepared Aluminum Alloy 5059-H131 for Three Different Pretreatment Methods

Abstract : Aluminum alloy 5059-H131 panels rolled to 0.25 thickness were prepared using Chemical Agent Resistant Coating (CARC) for evaluation under three different pretreatment conditions. The pretreatment conditions were abrasive blasted, a nonchromate pretreatment (NCP), and a commercial trivalent chromate pretreatment (TCP). The primer used was MIL-P-530223 and the topcoat was MILDTL-530394. Corrosion resistance was evaluated under GM 9540P5 and ASTM B 1176 neutral salt fog (NSF) methods. Adhesion was assessed under dry conditions using ASTM D 45417 pull-off and under wet conditions using ASTM D3359A8. Prior to coating, the conversion coated surfaces were compared for uniformity and color versus identically prepared AA5083 samples to determine whether or not the alloy differences will warrant modifications to current pretreatment processes.