| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1469302 | Corrosion Science | 2013 | 10 Pages |
The effect of the addition of water drops on the oxidation mechanisms of ceria coatings generated by cathodic electrodeposition onto a Ni-based superalloy was studied for short isothermal tests (50 h) between 900 °C and 1100 °C. Correlations between the oxidation kinetics and the growth mechanisms of the oxide scales were drawn and compared to conventional aluminide coating. The phase transformations were highlighted using Raman micro-spectrometry in combination with X-ray diffraction and SEM–EDS. Delayed transformation of θ-Al2O3, the appearance of pores and spallation occurred onto aluminides and the chemical inertness of ceria and the critical role of pre-oxidation was demonstrated.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Influence of water drops on the oxidation and degradation mechanisms. ► Critical role of pre-oxidation during heat treatment to stabilize Al2O3 and crystallize ceria. ► Improved oxidation resistance of ceria-coated samples partly explained by the growth of CeAlO3. ► Adsorption and release of water molecules but no dissociation due to ceria chemical stability. ► Spallation due to delayed transformation of theta-alumina onto aluminides with water drops.
