Abstract:
Interest in composite refractory ZrO2 – Al2O3 ceramics is due to the great prospects for their use
in extreme conditions (radiation exposure, thermal cycling, exposure to aggressive
environments) due to the high resistance to external influences of these ceramics. Moreover, the
features of high resistance to external influences for this type of ceramics are due to their
structural features and phase composition, which are controlled by the synthesis method and its
conditions. This paper presents the results of studying the influence of variations in the
annealing temperature of ZrO2 – Al2O3 ceramics obtained by solid-phase synthesis, as well as
establishing the effect of variations in the phase composition on strengthening and resistance to
thermal cycling. In the course of the research, using the X-ray phase analysis method, it was
found that at temperatures above 1200 °C, the formation of an impurity substitution phase of
the AlZrO2 type is observed, the formation of which leads to strengthening and increased
resistance to external influences. For ZrO2 – Al2O3 ceramic samples, in which the AlZrO2 phase
content was about 15-20 % (samples obtained at annealing temperatures of 1400 – 1500 °C), the
change in strength characteristics after 5 successive cycles was less than 3 %, which is more than
9 times lower than the similar change for two-phase samples obtained at an annealing
temperature of 1000 °C.
