In situ monitoring of corrosion processes within the bulk of AlMgSi alloys using X-ray microtomography

Susceptibility to localized corrosion of AlMgSi (AA6016 and AA6111) alloys in certain aggressive environments is high. In this study, synchrotron X-ray microtomography was used to monitor non-destructively corrosion processes within bulk materials. In the selected aggressive solutions, surface-deformed layers showed high localized corrosion susceptibility, but are more stable than the bulk of the alloy during corrosion propagation. In addition, exfoliation-like attack was observed as a transition from intergranular attack. This directed corrosion is not related to grain or crystallographic structure. Finally, intermetallic particles dissolution inside the materials after contact with aggressive solution of the intergranular corrosion path was evidenced. (C) 2008 Elsevier Ltd. All rights reserved.