STUDY OF THE KINETICS OF STRUCTURAL DAMAGE IN COMPOSITE CER-CER CERAMICS UNDER IRRADIATION WITH HEAVY IONS COMPARABLE TO NUCLEAR FUEL FISSION FRAGMENTS

The paper presents the assessment results of changes in the structural, strength and thermal parameters of cer-cer composite ceramics based on oxide compounds to radiation damage caused by high-temperature irradiation with heavy Kr 15+ and Xe 23+ ions. During the studies conducted, relationships between changes in structural parameters caused by deformation distortion of the crystalline structure and an increase in its volume, with the assessment results of the degradation of strength and thermal parameters, were established. It was determined that an elevation in the irradiation fluence leads to a cumulative effect of degradation of the properties of ceramics, while in the case of irradiation with heavy Xe 23+ ions, the effect of structural disordering and degradation of strength and thermal parameters is more pronounced than in the case of irradiation with Kr 15+ ions. This phenomenon is caused by differences in the value of ionization losses of incident ions, as well as the size of damaged areas that arise as a result of the interaction of incident ions with the crystalline structure of the damaged layer. At the same time, the most stable to radiation-stimulated softening processes are two-phase Al 2 O 3 – ZrO 2 ceramics, in which the presence of interphase boundaries leads to a growth in resistance to softening and destruction under high-dose irradiation. The presence of interphase boundaries acting as barriers that stop the diffusion of point and vacancy defects and reduce the degree of structural disorder of the damaged layer is considered as a mechanism for containing radiation damage in the case of two-phase ceramics.