STUDIES OF THE INFLUENCE OF TEMPERATURE FACTORS ON THE RATE OF STRUCTURAL DAMAGE ACCUMULATION IN COMPOSITE CERAMICS

The paper considers the influence of the temperature of heating under irradiation by heavy ions of composite ceramics on the processes of structural unstrengthening and disordering caused by the accumulation of radiation damage. The variation in irradiation temperature ranged from 300 to 1000 K, which made it possible to simulate radiation damage processes that were as close as possible to real operating conditions. The studies revealed a direct correlation between the changes in the degree of unstrengthening and bending strength disorder and the amount of volume-strain swelling of the crystal structure, as well as the contribution of thermal effects to the degradation of structural and strength properties of ceramics. According to the obtained data, it is established that the increase in the concentration of amorphous inclusions in the damaged layer, the presence of which has a direct dependence on both irradiation fluence and temperature, leads to a more expressed degradation of strength characteristics, indicating destabilization of ceramics resistance to the processes of unstrengthening at high-dose irradiation. Moreover, the degree of unstrengthening has a direct dependence on the irradiation temperature, which in case of considering the applicability of these ceramics as inert matrix materials requires consideration while predicting their operation lifetime. It was determined that the increase of irradiation temperature leads to more distinct destabilization of strength properties, in particular, decrease of hardness and bending strength at fluences of 10 13 –10 14 ion/cm 2 , the degradation of which exceeds the permissible values of 5% decrease from the initial values.