Localized Corrosion Behavior of the Sc Microalloyed Al-Cu-Li Alloy

Abstract

Corrosion behavior and microstructural evolution of the Sc microalloyed samples were investigated by OM, SEM, 3D surface profilometer, EBSD, TEM and STEM. The corrosion features of intragranular corrosion, sub-intergranular corrosion and sub-intragranular corrosion are confirmed in the studied alloys. The localized corrosion is associated with the local grain structure and distribution of T1 precipitate. Its initiation and propagation preferentially occur at the subgrain within unrecrystallized grain with high grain stored energy for Sc microalloyed samples.

Keywords: Keyworsd: Al-3.2Cu-1.5Li alloy, Sc microalloying, microstructures, Corrosion properties