Mémoires de Fin d’Etudes
Etablissement
Université de Béjaia - Abderrahmane Mira
Affiliation
Département de Génie des Procédés
Auteur
GUESSOUM, Khadoudj
Directeur de thèse
Kamel Belhamel (Professeur)
Co-directeur
Emmanuel Rocca (Maitre de conférence)
Filière
Génie des procèdes
Diplôme
Doctorat
Titre
Nouveaux alliages Zinc-Terres Rares pour des applications anticorrosion : Elaboration, Propriétés et Traitement de Surfaces
Mots clés
zinc, terres rares, électrochimie, EIS...
Résumé
The corrosion behaviour of new zinc-cerium alloys was studied and compared to pure zinc in corrosive media. Cerium addition to zinc (0.8 to 5 wt %) leads to an intrinsic improvement of the corrosion resistance of zinc, by the formation of a Ce enriched passive layer. XRD, EPMA and SEM studies show that the cerium is exclusively present in a Zn11Ce intermetallic phase, homogeneously dispersed in the zinc matrix. Stationary electrochemical techniques and impedance spectroscopy show that Ce addition to pure zinc enhances the corrosion resistance, with an optimal Ce amount between 0.8 and 1.5 wt%, by inhibiting both the cathodic and anodic reaction. Above 1.5 wt. % Ce, the benefit in terms of corrosion resistance obtained by the incorporation of Ce in the corrosion products is shaded by the galvanic coupling effect between the intermetallic phase and the matrix.
Statut
Validé