Phase analysis of plasma-sprayed zirconia-yttria coatings

Phase analysis of plasma-sprayed 8-wt%-yttria-stabilized zirconia (YSZ) thermal barrier coatings and powders was carried out by X-ray diffraction. Step scanning was used for increased peak resolution. Plasma spraying of the YSZ powder into water or onto a steel substrate to form a coating reduced the cubic and monoclinic phases with a simultaneous increase in the tetragonal phase. Heat treatment of the coating at 1150°Cfor 10 h in an Ar atmosphere Increased the amount of cubic and monoclinic phases. The implications of these transformations on coating performance and integrity are discussed