Corrosion of LY12 aluminum alloy in
sodium chloride solution
sodium chloride solution
(1. Department of Chemistry, Zhejiang University, Hangzhou 310027, China;
2. State Key Laboratory for Corrosion and Protection, Shenyang 110015, China)
2. State Key Laboratory for Corrosion and Protection, Shenyang 110015, China)
Abstract: The corrosion behavior of LY12 alloy in sodium chloride solution and its electrochemical noise were reported. The development of the micro-pits on the alloy surface was monitored by scanning electron microscopy, scanning tunneling microscopy, and electrochemical noise method. All the measurements show that the corrosion of LY12 alloy can be divided into two stages: a very reactive initial stage and a relative constant stable stage. The initial stage is corresponded to the adsorption of Cl- ions and its reaction with the oxide film and the dissolution of Mg containing particles. The stable stage is corresponded to the development of the micro-pits by the galvanic attack formed by Al-Fe-Cu-Mn containing particles and the matrix. The initial stage lasts about 2-3h while the stable stage dominates the whole corrosion process.
Key words: LY12 alloy; scanning tunneling microscopy; corrosion; electrochemical noise