Abstract:
The aim of this paper is to study the effect of variation in the component ratio of (1−x)Si3N4
-
xAl2O3 ceramics on the phase composition, strength and thermal properties of ceramics. To obtain
ceramics and their further study, the solid-phase synthesis method combined with thermal annealing
of samples at a temperature of 1500 ◦C typical for the initialization of phase transformation processes
was used. The relevance and novelty of this study lies in obtaining new data on the processes of
phase transformations with a variation in the composition of ceramics, as well as determining the
effect of the phase composition on the resistance of ceramics to external influences. According to
X-ray phase analysis data, it was found that an increase in the Si3N4 concentration in the composition
of ceramics leads to a partial displacement of the tetragonal phase of SiO2 and Al2
(SiO4
)O and an
increase in the contribution of Si3N4
. Evaluation of the optical properties of the synthesized ceramics
depending on the ratio of the components showed that the formation of the Si3N4 phase leads to an
increase in the band gap and the absorbing ability of the ceramics due to the formation of additional
absorption bands from 3.7–3.8 eV. Analysis of the strength dependences showed that an increase
in the contribution of the Si3N4 phase with subsequent displacement of the oxide phases leads to a
strengthening of the ceramic by more than 15–20%. At the same time, it was found that a change in
the phase ratio leads to the hardening of ceramics, as well as an increase in crack resistance.
