Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés
J. Phys. IV France 03 (1993) C7-1013-C7-1016
Microstructure of yttria stabilized zirconia-hafnia plasma sprayed thermal barrier coatingsH. IBÉGAZÈNE, S. ALPÉRINE and C. DIOT
ONERA, Materials Science Department, BP. 72, 92322 Châtillon cedex, France
Hafnia is an attractive candidate to build reliable and durable thermal barrier systems, due to its similarity to zirconia and its elevated structural transformation temperatures. We report here structural investigations of various plasma sprayed coatings composed of ZrO2 + x mole % HfO2 (x = 0, 25, 50 and 100), partially stabilized by 4.53 mole % yttria. X-Ray diffraction studies and TEM investigations show that, a metastable, non transformable, high yttrium content, t' phase is the only phase observed on the as-sprayed samples. Such results has not been yet related in the literature.
© EDP Sciences 1993