Effect of varying conditions of exposure to an aggressive medium on the corrosion behavior of the 2050 Al-Cu-Li alloy

The corrosion behavior of aluminum alloy 2050 was studied as a function of varying conditions of exposure to an aqueous NaCl solution. Two metallurgical states were considered, i.e., an as-received alloy (NHT) and aged samples (HT). After continuous immersion tests, the NHT samples were susceptible to intergranular corrosion, whereas intragranular corrosion was observed for the HT samples. For the NHT samples, cyclic corrosion tests, with alternate immersion - emersion periods, induced subgrain boundary dissolution, and for the HT samples, grain and/or subgrain boundary sensibilization was induced. Hydrogen content measurements suggested a hydrogen enrichment of the alloy under cyclic corrosion tests.