| Titre : | Interface thermodynamics of ultra-thin, amorphous oxide overgrowths on AlMg alloys (2011) |
| Auteurs : | E. Panda, Auteur ; L.P.H. Jeurgens, Auteur ; E. J. Mittemeijer, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Acta materialia (Vol. 58 N° 5, Mars 2010) |
| Article en page(s) : | pp. 1770–1781 |
| Note générale : | Métallurgie |
| Langues : | Anglais |
| Tags : | Interface energy Thermodynamics Alloy oxidation Amorphous oxides Ultra-thin oxide films |
| Résumé : | A thermodynamic model has been presented for the prediction of the type of initial, amorphous oxide overgrowth (i.e. am-Al2O3, am-MgO or am-MgAl2O4) on bare AlMg substrates as a function of the Mg alloying element content at the substrate/oxide interface, the growth temperature and the oxide-film thickness (up to 5 nm). On the basis of the macroscopic atom approach, expressions have been derived for the estimation of the energies of the interfaces between the AlMg substrate and the competing am-Al2O3, am-MgO and am-MgAl2O4 overgrowths. For all cases a strong driving force has been revealed for the interfacial (chemical) segregation of Mg. am-Al2O3 was found to be the most stable amorphous oxide phase on the AlMg substrate for T < 610 K; its relatively high stability is governed by a relatively low interface energy. The model predictions are in good agreement with corresponding experimental results on the chemical constitution of ultra-thin amorphous oxide films grown on Al- and Mg-based alloy substrates in the temperature range of 300–400 K. |
| DEWEY : | 669 |
| ISSN : | 1359-6454 |
| En ligne : | http://www.sciencedirect.com/science/article/pii/S1359645409007988 |
