Abstract:
The aim of this work is to study the properties of nanostructured (1 − x)ZrO2 − xCeO2
composite ceramics, depending on the content of oxide components, as well as to establish the
relationship between the phase composition of ceramics and strength properties. The choice of
(1− x)ZrO2 − xCeO2 composite ceramics as objects of study is due to the great prospects for using
them as the basis for inert matrix materials for nuclear dispersed fuel, which can replace traditional
uranium fuel in high-temperature nuclear reactors. Using X-ray diffraction, it was found that
the variation of the oxide components leads to phase transformations of the Monoclinic-ZrO2 →
Monoclinic − Zr0.98Ce0.02O2/Tetragonal − ZrO2 → Tetragonal − Zr0.85Ce0.15O2 → Tetragonal −
ZrCeO4/Ce0.1Zr0.9O2
type. As a result of mechanical tests, it was found that the formation of
tetragonal phases in the structure of ceramics leads to strengthening of ceramics and an increase
in crack resistance, which is due not only to an increase in the crystallinity degree, but also to the
effect of dislocation hardening associated with a decrease in grain size. It has been established that
a change in the phase composition due to phase transformations and displacement of the ZrO2
phase from the ceramic structure with its transformation into the phase of partial replacement of
Zr0.85Ce0.15O2 or Ce0.1Zr0.9O2
leads to the strengthening of ceramics by more than 3.5–4 times. The
results of resistance to crack formation under single compression showed that the formation of the
ZrCeO4 phase in the structure of ceramics leads to an increase in the resistance of ceramics to cracking
by more than 2.5 times.
