Description
Due to the health and environmental concerns associated with hexavalent chromium, tartaric sulphuric acid anodizing (TSA) has been introduced in the frame of the chromic acid anodizing (CAA) replacement. Hexavalent chromium however, was not only present in the anodizing electrolyte. It can also be found as a corrosion inhibitor in corrosion protection primers and paints. While a lot of research has been conducted on the primer formulation to replace Cr(VI), the focus of this work is on investigating the possible modifications of the anodic layer to enhance the corrosion protection system performance in combination with the new generation of chromate-free corrosion protection primers.Taking TSA as a reference process, anodizing parameters such as the electrolyte temperature, the anodizing voltage, the anodizing time or the tartaric acid concentration have been varied to study their effect on the resulting anodic oxide film formed on AA2024 cladded substrates. In particular, the incorporation or presence of tartrates in the oxide film has been studied by X-Ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) analysis. In addition, the degradation of these anodic films in aggressive acidic and alkaline environments have been investigated by means of Odd Random Phase Electrochemical Impedance Spectroscopy (ORP-EIS), resolved over time using the instantaneous impedance technique. Finally, industry-relevant corrosion and adhesion tests (filiform corrosion test, salt spray test, pull-off test and cross-cut test) have been conducted combining the anodic films under study with chromate-free and chromate-loaded model primers.
| Period | 24 Sep 2021 |
|---|---|
| Event title | EUROCORR 2021 |
| Event type | Conference |
| Degree of Recognition | International |