Corrosion behavior of 2A97 Al−Cu−Li alloys in different thermomechanical conditions by quasi-in-situ analysis

Abstract

As a promising material in the aircraft industry, 2A97 Al−Cu−Li alloy exhibits high corrosion susceptibility that may limit its application. In the present work, to illustrate the influences of precipitate and grain-stored energy on localized corrosion evolution in 2A97 Al−Cu−Li alloy, cold working and artificial aging were carried out to produce 2A97 Al−Cu−Li alloys under different thermomechanical conditions. Quasi-in-situ analysis, traditional immersion test and electrochemical measurement were then conducted to examine the corrosion behavior of 2A97 alloys. It is revealed that precipitate significantly affects Cu enrichment at corrosion fronts, which determines corrosion susceptibility of alloys, whereas grain-stored energy distribution is closely associated with localized corrosion propagation. It is also indicated that quasi-in-situ analysis exhibits a consistent corrosion evolution with traditional immersion tests, which is regarded as a proper method to explore localized corrosion mechanisms by providing local microstructural information with enhanced time and spatial resolutions.