Localised corrosion initiation and microstructural characterisation of an Al 2024 alloy with a higher Cu to Mg ratio

• DOI: 10.1016/j.corsci.2011.10.035
• Publication Date: 2011-11-03T16:01:47Z
• Authors: J.A. DeRose; T. Suter; A. Bałkowiec; J. Michalski; K.J. Kurzydlowski; P. Schmutz
• Keywords: Microscale chemistry; Pitting Corrosion

Abstract An Al 2024 (AA2024-T351) alloy having less Mg and a higher proportion of Cu to Mg (mass ratio ≈3.7) has been characterised to provide input data for microscale and macroscale corrosion models. The Al 2024 alloy microstructure has a significant presence of nanoscale dispersoid and microscale AlCuFeMnSi (2nd phase) intermetallic particles, but a smaller population of microscale S phase (Al 2 CuMg) and θ phase (Al 2 Cu) intermetallic particles. Microscale electrochemical data show that pitting potential (SCE) values for 2nd phase, S phase, or matrix overlap significantly. The localised corrosion susceptibility is affected by S and inhomogeneous 2nd phase particles.