Modification of porous anodic layers on AA2024 clad by atomic layer deposition and its effect on coating adhesion and oxide stability.

Mariana Paz Martinez-Viademonte (Speaker), Shoshan Abrahami (Contributor), Takahashi Yanagishita (Contributor), Dabiri Havigh, M. (Contributor), Karsten Thiel (Contributor), Wouters, B. (Contributor), Theodor Hack (Contributor), Malte Burchardt (Contributor), Terryn, H. (Contributor)

Activiteit: Talk or presentation at a conference

Description

The adhesion of organic coatings to anodic oxide films is known to be governed by (at least) two factors: the mechanical interlocking and the physico-chemical interactions at the oxide-coating interface. Separating these two contributions is a complicated task. Atomic layer deposition (ALD) enables the modification of the interface chemistry with virtually no effect on the morphology of the oxide film. Consequently, it is an interesting technique to de-couple morphological and physico-chemical contributions. However, the deposition of such coatings in industry-relevant oxides (ยต-thick layers, high aspect ratios) constitutes a challenge. In this work, alumina and titania have been deposited on tartaric sulphuric acid anodized AA2024 cladded substrates. The effectiveness of the deposition procedure has been assessed by X-Ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM) coupled with Energy Dispersive Spectroscopy (EDS). To study the effect of these chemical modifications on the adhesion of chromate-free and chromate-loaded corrosion protective coatings, scratch resistance adhesion tests have been performed. Finally, the degradation of the modified films in aggressive acidic and alkaline environments has been characterized by Odd Random Phase Electrochemical Impedance Spectroscopy (ORP-EIS), resolved over time using the instantaneous impedance technique.
Periode24 sep 2021
EvenementstitelEUROCORR 2021
EvenementstypeConference
Mate van erkenningInternational