STUDY OF PHASE FORMATION PROCESSES IN CER-CER TYPE INERT MATRICES BASED ON OXIDE COMPOUNDS

The purpose of this work is to study the processes of phase formation in the samples (1-x)ZrO₂ – xAl₂O₃ ceramics depending on the variation of the oxide components, as well as to establish changes in the structural parameters and degree of crystallinity. The choice of zirconium and aluminum oxides as the basis for cer-cer inert matrices for nuclear fuel is due to their physical, chemical, structural and mechanical properties, the combination of which will produce a new type of ceramics with great potential in the field of nuclear fuel. These oxide compounds have high thermal stability and resistance to high temperatures, which also allows their use as a basis for disperse nuclear fuel for new-generation hightemperature nuclear reactors. The method of mechanochemical milling followed by thermal annealing was chosen to obtain ceramics based on oxide compounds. The choice of grinding conditions, as well as the subsequent thermal annealing was chosen to initiate the processes of phase transformations and structural changes as a result of thermal influence and partial relaxation of the deformation distortions and metastable formations initiated during grinding. The X-ray diffraction method was chosen as the main method to study the processes of phase transformation and structural changes. During the studies it was found that the addition of aluminum oxide leads to the structural ordering of the main monocline phase ZrO₂, as well as the formation of solid solutions of substitution and introduction. At equal concentrations of the oxide components using the method of X-ray phase analysis was established polymorphic phase transformation in zirconium dioxide, the presence of which indicates the processes of phase transformation arising from the addition of zirconium oxide and changes in the phase formation processes.

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