Spatiotemporally resolved corrosion protection of AA2024-T3 by a lithium-based conversion layer

In this work, the corrosion mechanism of AA2024-T3 covered by a lithium-based conversion layer is studied with high spatial and temporal resolution. Although the aluminium alloy surface is protected by a multi-layered conversion layer, areas around intermetallic phases (IMPs) represent weak spots due to an insufficient generation of a...

Initial characterisation of mechanical and corrosion properties of stationary shoulder friction stir welded bare and Alclad AA2024-T3 butt joints

Aluminium alloy AA2024-T3 is a lightweight and damage tolerant material, and is therefore often used in aerospace applications. However, this alloy is difficult to weld using conventional fusion welding techniques due to defects caused by the meld pool.<br/> <br/>Friction stir welding (FSW) was developed by The Welding Institute (TWI) in 1991 in...

Hybrid sol-gel coatings applied on anodized AA2024-T3 for active corrosion protection

The effect of the presence of an anodic film and hybrid sol-gel coating loaded with corrosion inhibitors was evaluated as a strategy for enhanced barrier and active corrosion protection of aluminium alloy 2024-T3. In this study, AA2024-T3 specimens were anodized in a modified sulphuric-citric acid bath (SCA) as the first layer of a corrosion...

Laterally-resolved formation mechanism of a lithium-based conversion layer at the matrix and intermetallic particles in aerospace aluminium alloys

Lithium leaching coatings have recently been developed as eco-friendly active corrosion protection technology for aerospace aluminium alloys (AAs) by the formation of a conversion layer at coating defects. While general conversion layer formation characteristics were studied and reported before, here we study the local layer formation process...

Lithium and Cerium based sol-gel coatings for corrosion protection of AA2024-T3

Due to the demand of reducing the weight of aircrafts to reduce the carbon consumptions without compromising the mechanical properties, aluminium alloy AA2024-T3 has been widely applied in the aircrafts’ manufacture. However, the alloying elements which ensure the mechanical properties also could increase the susceptibility of localized...

The importance of the time-effect in electrochemical studies of corrosion inhibitors

The corrosion protection of metallic substrates with corrosion inhibitors, either in solution or dispersed in a coating formulation, has been the focus of many research topics for many decades and has intensified in recent years even more with industry moving away from hexavalent chromium (Cr(VI))- based corrosion inhibitors. While mainly...

Investigation of novel Cr6+-free anodising pre-treatments for enhanced corrosion protection of aluminium alloy 2024-T3

Hexavalent chromium has been the industry standard for corrosion protection for many years. Its unsurpassed active corrosion inhibiting capabilities, its incredible versatility and its economic benefits made it a popular all-rounder. Nowadays the widely known toxic and carcinogenic nature have restricted its use within the European Union. More...

Cross-sectional characterization of the conversion layer formed on AA2024-T3 by a lithium-leaching coating

This work focuses on the cross-sectional characterization of the protective conversion layer formed on AA2024-T3 by lithium-leaching from a polyurethane coating in a corrosive environment. The layer shows a multi-layered arrangement comprising nanoscopic local phases. Transmission electron microscopy (TEM) and complementary high-resolution...