Influence of Y2O3 distribution on the rate of tetragonal to monoclinic phase transformation of yttria-stabilized zirconia during hydrothermal aging

摘要

Tetragonal to monoclinic phase transformation ofyttria-stabilized zirconia, namely plasma-sprayed coatings andsintered bodies containing 4-8 mass % Y2O3 during hydrothermalaging was investigated with respect to Y2O3 distribution using 1μmφ area from electron probe microanalysis (EPMA) and 20 μmφarea from transmission electron microscopy (TEM) analysis. Phasetransformation at 473K was prevented only in plasma-sprayedcoatings having more than 6.7 mass% Y2O3 in 20μmφmicroscopic area. Further-more, it was confirmed influence ofY2O3 distribution on the rate constants of this phasetransformation was observed at 368K.