Soutenance de Emre YALAMAC

Le 11 juin 2010 à 09h30 IZMIR (Turquie) Thèse de DOCTORAT en cotutelle internationnale de l'UNIVERSITE de GRENOBLE (France) et de l'IZMIR INSTITUTE of TECHNOLOGY (Turquie), spécialité Matériaux, Mécanique, Génie Civil, Electrochimie dans le cadre de l'Ecole Doctorale « Ingénierie-Matéraiux, Mécanique, Energétique, Environnement, Procédés, Production » et de « The Graduate School of Science and Engineering » Thèse préparée dans le laboratoire SIMaP (France) et au Department of Mechanical Engineering (Turquie) sous la direction conjointe de M. Claude Paul CARRY & M. Sedat AKKURT

Résumé Densification and microstructural evolution during co-sintering of alumina (Al2O3) - zirconia (Y-ZrO2) and alumina - spinel (MgAl2O4) co-pressed bi-materials were investigated. Before co-sintering of bi-materials, sintering behaviours of their end-members were studied by dilatometer to determine the degree of shrinkage mismatches between the end-members. The effects of precoarsening and two-step sintering on the densification and microstructure of spinel ceramics were investigated. Interfaces between alumina and spinel after co-sintering treatment at 1400-1500°C were investigated. A spinel interlayer with columnar grains of up to 40 µm length and 5 µm width was observed after 16 hours at 1500 °C. Growth rate of this interlayer from spinel toward alumina was found to follow parabolic kinetics, controlled by a diffusion mechanism of probably lattice diffusion of O2- ions. Diffusion couple tests of spinel and alumina produced the same columnar spinel grains at the interface

Membres du Jury Prof. Muhsin CIFTCIOGLU, Président (TR) Dr. Guillaume BERNARD-GRANGER, Rapporteur (FR) Prof. Zafer EVIS, Rapporteur (TR) Prof. Claude Paul CARRY, Directeur de thèse (FR) Prof. Sedat AKKURT, Directeur de thèse (TR)