Corrosion of AA2024-T3 Part I. Localised corrosion of isolated IM particles

Polished specimens of AA2024-T3 were immersed for various times up to 120 min in 0 1 M NaCl The development of corrosion around isolated intermetallic particles was monitored using scanning electron microscopy with energy dispersive X-ray spectroscopy (EDXS) The earliest stages of attack started with localised corrosion of the S-phase particles resulting in dealloying which was followed by trenching around these particles Subsequently trenching was observed around cathodic particles where trenching started with AlCuFeMn particles with Cu/Fe ratios typically around 2 5 and then progressed to AlCu-FeMnSi particles This latter category of particles had a much lower Cu/Fe ratio typically 0 5 Crown Copyright (C) 2010 Published by Elsevier Ltd All rights reserved