Characterisation and understanding of the corrosion behaviour of the nugget in a 2050 aluminium alloy Friction Stir Welding joint

Vincent Proton (1) , Joël Alexis (2) , Eric Andrieu (1) , Jérôme Delfosse (3) , Marie-Christine Lafont (1) , Christine Blanc (1)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 LGP - Laboratoire Génie de Production
3 EADS IW - EADS Innovation Works [Suresnes]

The corrosion behaviour of the nugget of a Friction Stir Welding joint employing a 2050 Al-Cu-Li alloy was investigated. The results showed that the nugget was susceptible to both intergranular and intragranular corrosion. Such corrosion behaviour was related to microstructural heterogeneities observed on a microscopic scale. Furthermore, heterogeneities in the corrosion behaviour of the nugget observed on a macroscopic scale were evidenced by a different corrosion behaviour from the top to the bottom of the nugget and by a localisation of the corrosion damage related to the ''Onion ring structure''. Critical microstructural parameters were identified to explain the results.

Mots clés: Aluminium; Alloy; Polarisation; TEM; Intergranular corrosion; Welding

Domaines: Matériaux

Vincent Proton, Joël Alexis, Eric Andrieu, Jérôme Delfosse, Marie-Christine Lafont, et al.. Characterisation and understanding of the corrosion behaviour of the nugget in a 2050 aluminium alloy Friction Stir Welding joint. Corrosion Science, 2013, vol. 73, pp. 130-142. ⟨10.1016/j.corsci.2013.04.001⟩. ⟨hal-00932432⟩