VOL 96, No. 5 (2023)

The results of an investigations into the effect of filamentous striae with birefringence from 3 to 15 nm/cm in SO-115M glass-ceramic on the manufacturing quality of optical parts for ring lasers and the exact characteristics of laser gyroscopes based on them are presented. It is shown that the presence of striaes with stresses of no more than 15 nm/cm in SO-115M glass-ceramic does not depend on the speed of manufacturing the resonator optical circuit and the quality of its assembly. The presence of striaes in the output mirror additional backscattered of a ring laser may have the destination of lock-in zone. Correct adjustment of the output mirror allows to reduce scattering and reveal the growth of the lock-in zone in laser gyroscope. It is shown that the accuracy of the laser gyroscope improves by the quality mirror substrates, the geometry of the resonator body, and increases the accuracy of scattering inside the resonator.

The transformation of substances under extremely high pressures and temperatures is an actual direction both in the field
of solid state physics and materials science, and for natural objects. Among the latter, the most interesting are ultrahigh-pressure high-temperature glasses recently found at the Kara giant meteorite crater (Pai-Khoi, Russia), formed from impact melts at pressure about 60 – 80 GPa and the temperature range of 2300 – 2500 °C. These glasses are characterized
by unusual structural and phase state features that require deeper study to clarify their physical properties and the possibility
of using them as prototypes of innovative materials. Experimental modeling of the impact process in laboratory conditions allows to identify the nature of phase transformations during impactogenesis. Here the modeling of the impact process
has been carried out by short-pulse laser radiation (0.5 ms) on the example of clay-containing siltstones and limestones with and carbonaceous components. The impact glasses have been produced from aluminosilicate and quartz components of the host target rocks of the Kara target under pressure conditions ?90 GPa and temperatures ?7000 °C. To study
the synthesized products of the impact glasses, high resolution methods have been used – Raman spectroscopy and scanning electron microscopy with microprobe analysis. The provided studies have shown that under the extreme conditions
the impact glasses of a specific composition containing a high concentration of Ca and carbon are formed. Thus, the experiments conducted have shown the possibility of obtaining glasses of a wide composition, including carbon-containing glass, which can be used for further studies aiming to develop new materials and technologies of their producing.

The article is devoted to the development of an original production method for estimating the specific energy of destruction of ceramic compositions of the “abrasive grain–ceramic binder–pores” system. The results of experimental studies
and theoretical calculations that form the basis of the proposed method. Recommendations for its use are given.

The article presents a study of the properties and structure of underglaze paints with different cobalt pigments and the development on their basis of the composition of the paint for porcelain Gzhel, resistant to changes in temperature and gas environment during firing, as well as less labor-intensive in manufacturing. Underglaze paints based on cobalt oxide and pigments synthesized in the chemical systems Cо–Al–Si and Co–Si have been studied. Their behavior during painting, color characteristics after firing in the range of 1200 – 1320 °C, resistance to the formation of defects with changes in temperature and gaseous medium during firing were analyzed. The relationship between the structure of paints on porcelain and its decorative properties has been established. A paint with an optimal combination of pigments of the Cо–Al–Si and Co–Si systems has been introduced into production, corresponding in terms of decorative effect to paint with Co3O4, but resistant to “metallization” during firing and less expensive.

The technology of facing material based on mechanically activated cullet modified with sodium hydroxides has been developed. The phase composition, macro- and microstructure of the lining material are investigated. It is established that the microstructure of a composite modified with sodium hydroxide in the interpore space is represented by lamellar crystals of sodium meta-, di- and orthosilicates. The optimal composition for obtaining a facing material with a compressive strength of 24.7 MPa and a softening coefficient of 0.91 has been established.

The results of diamond-abrasive treatment of the reverse side of silicon carbide semiconductor plates of polytypes 4H and 6H are presented. Dimensions of surface microcracks of ceramic plates after abrasive treatment with pastes with diamond powder of different grain size are investigated, and also relationship between length of surface microcrack and rate of material removal depending on technological modes of diamond-abrasive treatment is established. As a result, a new method of single-sided abrasion treatment of thin ceramic plates is proposed, which ensures reduction of crack formation.

The results of studying the behavior of analcime-bearing rocks of the Timan region (Komi Republic) under high-temperature firing (1200 – 1280 ?С) were presented. The mineral composition and physical characteristics (apparent density, water absorption, open porosity, thermal conductivity) of the resulting ceramics were determined. The influence of the mineral composition of the initial analcime-containing rocks on the bloating and physical characteristics of fired ceramics was shown. Porous materials with low apparent density (0.37 – 0.39 kg/m3), water absorption (up to 4.3 %), and thermal conductivity (0.09 – 0.10 W/m??С) were obtained. The obtained results show the prospects of using analcime-bearing rocks with a certain mineral composition for producing heat-insulating materials.

The activity of the remarkable scientist V.F. Solinov is considered.