THE BEHAVIOR OF ANODIZED ALUMINUM IN SEA AND BRACKISH-WATER

The possibility of preventing pitting corrosion of aluminum and alumin um-based alloys in marine environments by anodization was investigated . For six months, commercial-purity-grade aluminum and specimens of Al loys 3003 and 5083, which are frequently used in marine applications, were fully immersed in synthetic sea water and brackish water from the Huelva estuary. The behavior of sealed and unsealed anodized specimen s is compared with that of unprotected specimens. Changes in the porou s and barrier layers of anodized aluminum were studied by electrochemi cal impedance spectroscopy. Results were then compared with weight cha nges recorded during the exposure period and the specimen appearance a t the end.