Abstract:
The main purpose of this study is to test a hypothesis about the effect of grain size on the
resistance to destruction and changes in the strength and mechanical properties of oxide ceramics
subjected to irradiation. WO3 powders were chosen as objects of study, which have a number of
unique properties that meet the requirements for their use as a basis for inert matrices of dispersed
nuclear fuel. The grain-size variation in WO3 ceramics was investigated by mechanochemical
grinding of powders with different grinding speeds. Grinding conditions were experimentally
selected to obtain powders with a high degree of size homogeneity, which were used for further
research. During evaluation of the strength properties, it was found that a decrease in the grain size
leads to an increase in the crack resistance, as well as the hardness of ceramics. The increase in strength
properties can be explained by an increase in the dislocation density and the volume contribution
of grain boundaries, which lead to hardening and an increase in resistance. During determination
of the radiation damage resistance, it was found that a decrease in grain size to 50–70 nm leads to
a decrease in the degree of radiation damage and the preservation of the resistance of irradiated
ceramics to destruction and cracking.
