The crystallographic corrosion and its microstructure in an Al-Cu-Li alloy

The localised corrosion behaviour and the microstructure in an Al-2.23Cu-0.96Li (wt%) alloy were systematically investigated by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The major strengthening precipitate in the peak-aged alloy is the Guinier-Preston-Bagaryatsky (GPB) zones which nucleate and grow in the < 001 >(Al) directions, while the crystallographic corrosion appears and propagates along the {111}(Al) planes. At the nanometre scale, the features of crystallographic corrosion are made up of many step-like {100}(Al)-oriented sidewalls which are closely associated with the GPB zones. The GPB zones are unable to affect the overall propagation direction of the crystallographic corrosion, but is related to the formation of the nanoscale localised corrosion morphology of the crystallographic corrosion. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study systematically investigated the localized corrosion behavior and microstructure of an Al-2.23Cu-0.96Li (wt%) alloy using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the GPB zones in the alloy do not significantly affect the overall propagation direction of crystallographic corrosion, but are closely related to the formation of nanoscale localized corrosion morphology in the crystallographic corrosion.