Degradation of SPS-Fabricated YSZ and Nd2O3-YSZ Ceramics in Supercritical Water

作者：Siebert Timmer A; Bichler L^*

来源：Journal of Materials Engineering and Performance, 2016, 25(4): 1426-1435.

DOI：10.1007/s11665-016-1983-x

• degradation
• neodymium oxide
• Nd2O3
• spark plasma sintering
• supercritical water
• zirconia
• ZrO2

Zirconia (ZrO2) ceramics are being considered as a candidate material for thermal insulating barriers in pressure tubes used in the supercritical water (SCW) nuclear reactors. However, the literature suggests that zirconia may undergo a detrimental phase transformation which is accelerated in aqueous environments. In this research, 8 mol% Yttria-Stabilized Zirconia (YSZ) ceramics with the addition of 5 and 10 mol% Nd2O3 were manufactured via spark plasma sintering (SPS) process and subsequently subjected to a SCW environment. The weight losses and microstructural evolutions of these materials during SCW exposure were studied. The results suggest that doping YSZ with Nd2O3 significantly decreased the degradation rate of the YSZ ceramic and improved its structural stability. X-ray diffraction studies revealed that after degradation testing, the Nd2O3 helped to retain the desirable cubic phase of YSZ matrix. In the case of pure YSZ ceramic, a phase change of the matrix toward the monoclinic lattice was observed and likely contributed to the ceramic's disintegration in SCW environment.

• 出版日期2016-4