Study of Phase Transformations in ZrO2 Ceramics Stabilized by Y2O3 and Their Role in Changing Strength Characteristics and Heat Resistance

The results obtained reflect the determination of the possibility of the stability enhancement of the strength and thermal parameters of zirconium-containing ceramic materials via the addition of a stabilizing additive in the form of Y2O3. According to the data obtained, a connection between phase transformations caused by the addition of the stabilizing Y2O3 additive and an increase in strength characteristics, the growth of which is also due to the formation of the dispersion hardening effect during grain size reduction, was established. It was found that the formation of the stabilized Zr(Y)O2 phase results in thermal conductivity reduction, while the formation of the perovskite phase YZrO3 has a positive effect on the thermophysical parameters of ceramics. It was determined that the change in phase composition associated with the formation of the tetragonal Zr(Y)O2 phase at low dopant concentrations leads to an increase in strength characteristics, but a decrease in thermal conductivity, while the formation of the YZrO3 phase in the structure contributes to a growth not only in strength, but also thermophysical parameters.