Characterization of TiO_2-Doped Yttria-Stabilized Zirconia (YSZ) for Supercritical Water-Cooled Reactor Insulator Application

摘要

In this study, TiO_2-doped YSZ samples were tested in supercritical water (SCW) to evaluate their corrosion behavior. The doped samples were produced by mechanically alloying standard 7 wt.% Y_2O_3-ZrO_2 with 5, 10, and 15 wt.% of TiO_2 first. The bulk sample pieces were then obtained using plasma spraying of the alloyed powder materials followed by sintering. The results showed that the weight changes for 5TiYSZ and 10TiYSZ after 1000 h of exposure in SCW were negligible and the sample surfaces did not exhibit any indication of corrosion. In comparison to the reference materials (Al_2O_3 and 7YSZ) processed using the same method, the rate of weight change followed the order of Al_2O_3 > 7YSZ, 15TiYSZ > 10TiYSZ > 5TiYSZ. As several TiO_2-doped 7SYZ compositions also display increased fracture toughness and reduced thermal conductivity, they may be considered as potential candidates for thermal insulation in a SCW-cooled nuclear reactor.