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A critical requirement for candidate materials used in inert matrices of dispersion-type nuclear fuel or in the immobilization of spent fuel with a high content of minor actinides is their ability to withstand aggressive conditions, including high temperatures, radiation, mechanical loading, and friction[1-2]. Ceramics based on Al₂O₃ and Y₂O₃-stabilized ZrO₂ are considered promising owing to the possibility of forming composite structures comprising an alumina matrix with embedded ZrO₂ grains [3-5]. At the same time, conditions such as reproducibility of synthesis results, scalability, and ease of manufacture are imposed on the methods for obtaining ceramics. The method of mechanochemical solid-state synthesis holds great promise for the development of ceramic materials and allows for scalability of the fabrication technology due to its relatively low cost.
The aim of this study is to investigate the effect of Y₂O₃ as a dopant on the mechanical and thermophysical properties of ZrO₂–Y₂O₃ ceramics under different variations of phase composition. Analysis of the phase composition showed that when the ratio of components is varied due to a change in the concentration of the Y2O3 dopant, processes of polymorphic transformations of the m – ZrO2 → t- Zr(Y)O2 type occur, so that an increase in the proportion of Y2O3 in the composition leads to the formation of the pyrochlore phase Y2Zr2O7, and at high concentrations to the formation of inclusions in the form of Y3Al5O12 grains.
The results of polymorphic transformations in ZrO2 – Y2O3 ceramics obtained by changing the amount of the stabilizing dopant Y2O3 lead to strengthening of the ceramics by 30 – 50% compared to unstabilized ceramics. At the same time, the thermal conductivity coefficient of ceramics containing Y₂Zr₂O₇ and Y₃Al₅O₁₂ phases decreases, while the thermal insulation efficiency increases twofold.
References
1. Kadyrzhanov, K. K., Kozlovskiy, A. A., Konuhova, M., Popov, A. I., Shlimas, D. D., & Borgekov, D. B. (2024). Determination of gamma radiation shielding efficiency by radiation-resistant composite ZrO2–Al2O3–TiO2–WO3–Nb2O5 ceramics. Optical Materials, 154, 115752.
2. Brykała M. et al. Microstructural characterization and thermal analysis of sintered Ce/Nd doped zirconia ceramics for nuclear applications: M. Brykała et al //Journal of Thermal Analysis and Calorimetry. – 2025. – P. 1-14.
3. Hostaša, J., Pabst, W., & Matějíček, J. (2011). Thermal conductivity of Al2O3–ZrO2 composite ceramics. Journal of the American Ceramic Society, 94(12), 4404-4409.
4. Sathish, S., & Geetha, M. (2016). Comparative study on corrosion behavior of plasma sprayed Al2O3, ZrO2, Al2O3/ZrO2 and ZrO2/Al2O3 coatings. Transactions of Nonferrous Metals Society of China, 26(5), 1336-1344.
5. Zhang, H., Lu, H., Zhu, Y., Li, F., Duan, R., Zhang, M., & Wang, X. (2012). Preparations and characterizations of new mesoporous ZrO2 and Y2O3-stabilized ZrO2 spherical powders. Powder technology, 227, 9-16.
