A method for the direct determination of intercalated water in high-purity boron oxide has been developed. Comparative studies of the residual intercalated water and OH-group content in a commercial product and our own high-purity boron oxide have been conducted. It has been shown that under traditional high-purity boron oxide synthesis conditions, a clear correlation between the residual intercalated water content and the OH group content is impossible.
The aluminoborosilicate glass of basic composition was tested for the perlite-containing materials syntheses. The influence of the proportion of perlite filter powder in the initial mixture on the composition, structural features and individual physical properties of the synthesized materials was studied. A conclusion has been formulated regarding the conditions for implementing the vitrification process in a melt based on aluminosilicate glass of the selected composition of perlite-containing radioactive pulps in industrial installations.
The effect of electron-beam sintering in the fore-vacuum pressure range (8…10 Pa) on the density, structure, and phase composition of the sintered Al2O3–Cu composite with a component mass ratio of 10:1 was investigated. It was established that the maximum density of the sintered composite (2.85 g/cm3) is achieved at a temperature of 1300 °C. It was also shown that upon heating above 1100 °C, copper migrates to the surface and evaporates, forming a depleted near-surface layer. The metallic Cu phase was detected only at 1100 °C (2 wt. %), whereas at higher temperatures only traces of CuO were present. The obtained results confirm the feasibility of producing gradient Al2O3–Cu structures using this method.
The results of solid-phase synthesis of ceramic samples of a new system(1 – x)BiFeO3–xBa(Ti1 – ySny)O3 (x = 0…0,40, y = 0,05; 0,10) are presented. X-ray phase analysis confirmed that the synthesized samples form solid solutions with a perovskite structure. It was established that an increase in the concentration x leads to a change in symmetry from rhombohedral to pseudocubic. During the study of dielectric properties over a wide frequency range (25 Hz…500 kHz) and temperature range (80…900 К), anomalies were observed in the behavior of the dielectric permittivity ? (T, f) and the dielectric loss tangent tan? (T, f), caused by relaxation processes and phase transitions.
The results of research work conducted in collaboration with the “Elite Building Ceramics” brick factory on the development of low-temperature glazed compositions and their application technology to soft-molded linear bricks are presented. A color palette of blue-green shades of the glazed layer with a decorative effect of speckled inclusions has been obtained. A technological scheme has been developed, and technological parameters for the production, storage, and application of the glaze have been elaborated. The obtained decorative coatings have been recognized as reference samples. The proposed glazed compositions will allow for the expansion of the color palette of manufactured soft-molded linear bricks.
The possibility of replacing bottom ash waste (ASW), which serves as the main raw material for the synthesis of such materials, with drill cuttings (DC) was investigated. It was found that DC, unlike ASW, has high crystallinity and low reactivity, which limits its content in the raw mixture. Experiments have proven that the optimal replacement is 25 wt. % of ASW with DC. The resulting material is characterized by a uniform porous structure with an average pore size of 1.8 ± 0.2 mm, a density of 311 kg/m3, and a compressive strength of 1.02 MPa, which is comparable to a sample based on pure ASW (the difference in properties does not exceed 3 %). Increasing the DC content above 25 wt. % leads to an increase in the SiO2/Al2O3 ratio, premature gas evolution, and pore collapse, which degrades the thermal insulation properties. The obtained results demonstrate the possibility of using large-tonnage drilling waste for the production of building thermal insulation materials.
The effectiveness of an argon ion cluster beam for polishing the surface of corundum ceramics was investigated. Using atomic force microscopy, changes in the surface relief of VK-100 ceramics were studied after treatment with argon cluster ions in various modes: with small and large average cluster ion sizes. The ranges of lateral sizes of irregularities at which smoothing of the ceramic surface is observed were determined.
The article presents the results of a study on the elemental and chemical–mineralogical composition, as well as the structure and morphology of samples of Shekhzheli basalt, using chemical analysis, X-ray diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscopy (SEM). The main thermo mechanical characteristics of fired basalt rock samples from the Shekhzheli deposit were determined in the temperature range of 1000…1200 °C.
The article presents the development of a technique for producing transparent silica glass products using LCD-stereolithography using a photopolymer composite. It is shown that ultrasonic treatment of the composite makes it possible to destroy agglomerates of SiO2 nanoparticles and achieve a more uniform distribution of them in the organic matrix, significantly reducing the sintering temperature. Optimal printing and removal modes of the polymer matrix have also been determined. As a result of sintering at a temperature of 1175 °C, transparent monolithic silica glass samples with a density of 2,19 g/cm3 and a shrinkage of ~30 % were obtained. The light transmission investigation showed that the samples provide 83,5 % transmission in the visible region of the spectrum.
