Abstract
The paper presents the results of the assessment of reaction phase transformations in composite (1-x)ZrO 2 –xSiC ceramics associated with a change in the ratio of components in the composition of ceramics during thermal sintering. The analysis was carried out using X-ray phase analysis, Raman spectroscopy and optical spectroscopy methods. According to the results of X-ray phase analysis of the studied samples of composite (1-x)ZrO 2 –xSiC ceramics, it was established that an increase in the proportion of SiC to 0.5 in the composition of ceramics leads to the initialization of reaction phase transformations of the m-ZrO 2 → SiO 2 +ZrO 2 → t-ZrSiO 4 type, which result in the formation of the tetragonal phase of zircon. It was established that the formation of the zircon phase occurs due to the thermal oxidation of silicon carbide, which results in the formation of silicon oxide and an increase in the concentration of oxygen vacancies in the composition of ceramics. It was determined that at a SiC concentration of 0.5 M, the phase composition of ceramics is represented by a mixture of zircon ZrSiO 4 phases and a hexagonal SiC phase with a small admixture of silicon oxide SiO 2 in the composition. An analysis of the optical transmission spectra of the studied ceramics showed that the formation of ZrSiO 4 is accompanied by an increase in oxygen vacancies, as well as a shift in the fundamental absorption edge.