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Description
The main aim of this study is to determine the mechanisms of defect formation during combined (sequential) irradiation of composite SiC – ZrO2 ceramics with heavy Kr15+ and Xe23+ ions, as well as to identify the role of changes in irradiation conditions on the processes of destabilization of the structural and strength properties of ceramics. Interest in this topic is due to the possibilities of using these composite SiC – ZrO2 ceramics as materials for creation of inert matrices of dispersed nuclear fuel, alongside containers for storage of spent nuclear fuel.
During the studies conducted, it was determined that sequential irradiation with heavy Kr15+ ions with an energy of 147 MeV and a fluence of 2.5×1012 ion/cm2 and heavy Xe23+ ions with an energy of 230 MeV and a fluence of 2.5×1012 ion/cm2 leads to significant differences in the mechanisms of defect formation than in the case of irradiation with heavy Kr15+ and Xe23+ ions with fluences of 5×1012 ion/cm2 separately. It has been determined that in the case of successive exposure to heavy ion irradiation, defect formation processes are inhibited by the formation of a deformed layer during irradiation with Kr15+ ions, which acts as a buffer inhibiting layer during defect formation initiated by irradiation with heavy Xe23+ ions. According to the data obtained, the formation of structurally altered deformed areas arising along the trajectory of ion movement in the damaged layer with their subsequent overlapping, in the case of irradiation with Xe23+ ions is more pronounced than in the case of irradiation with Kr15+ ions, which is primarily due to differences in the values of ionization losses of ions arising along the trajectory of ion movement in the material, which in turn leads to an increase in the diameter of damaged areas. In this case, with successive irradiation with Kr15+ and Xe23+ ions, the formation of interfaces between defective regions that arose along the trajectory of the Kr15+ ions and the non-irradiated material leads to the inhibition of defect formation processes during subsequent irradiation with heavy Xe23+ ions. The observed effect of changes in the processes of destabilization of the structural and strength properties of SiC – ZrO2 ceramics in the case of combined action of heavy Kr15+ and Xe23+ ions is in good agreement with the results of works related to the study of the possibilities of radiation-induced hardening of materials using heavy ion beams.
