Quasi in situ analytical TEM to investigate electrochemically induced microstructural changes in alloys: AA2024-T3 as an example

A quasi in situ method using a specially developed holder is presented to follow electrochemically induced microstructural changes on a nanometre scale using analytical transmission electron microscopy (TEM). By following a specific specimen area after repeated exposure to oxygen bubbled through aqueous HCI of pH = 3, de-alloying of a grain-boundary precipitate of similar to 200 nm was observed by monitoring the changes in the EELS copper L-2,L-3-edge and EFTEM elemental maps. These results, supporting the existing models of de-alloying of copper rich precipitates in aluminium alloys, demonstrate the effectiveness of the quasi in situ specimen holder for analytical TEM studies of corrosion. (C) 2012 Elsevier Ltd. All rights reserved.