1. High-temperature stability of CSZ, YSZ, and MSZ ceramic materials in CaCl2-CaF2-CaO molten salt system.
- Author
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Yoo, Bung-Uk, Kwon, Suk-Cheol, Cho, Soo-Haeng, Nersisyan, Hayk H., and Lee, Jong-Hyeon
- Subjects
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CERAMIC materials , *FUSED salts , *ZIRCONIUM oxide , *CALCIUM chloride , *HIGH temperatures , *ELECTROLYTIC reduction - Abstract
Abstract This study investigated the high-temperature stability of CSZ, YSZ, and MSZ specimens in a CaCl 2 -CaF 2 -CaO molten salt at 1200 °C for the application of the materials as oxygen-ion-conducting solid-oxide membrane anodes in the electroreduction process of metal oxides. YSZ exhibited the lowest degradation among the tested specimens in a high-temperature stability test, whereas CSZ showed the highest degradation. The weight loss was not severe with concentrations of CaO up to 10 wt%. CSZ showed peaks for m-ZrO 2 , YSZ showed peaks for t-ZrO 2 and CaZrO 3 , and MSZ showed peaks for t-ZrO 2 and m-ZrO 2 in 0 wt% CaO. In the case of 5 wt% CaO, all specimens exhibited m-ZrO 2 and CaZrO 3 peaks, In the cases of 10 wt% and 20 wt% CaO, CSZ and MSZ showed peaks for CaZrO 3 , and YSZ showed peaks for m-ZrO 2 and CaZrO 3. While CSZ and MSZ became significantly looser as the CaO concentration was increased to 10 wt%, YSZ became significantly denser due to the formation of a protective layer and attack dependent on the solubility of CaO in the molten CaCl 2. In terms of long-term operation, YSZ was demonstrated to possess superior high-temperature stability compared to CSZ and MSZ, and CaO concentrations from 5 wt% to 10 wt% were found to be significantly more stable than other concentrations. Highlights • The degradation mechanism of CSZ, YSZ, and MSZ in CaCl 2 -CaF 2 -CaO molten salt is proposed. • The formation of CaZrO 3 acts as a protective layer. • YSZ shows high degradation resistance to CaCl 2 -CaF 2 molten salt that contains up to 10 wt% of CaO. • In view of long-term operation, YSZ is demonstrated to possess superior high-temperature stability compared to CSZ and MSZ. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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