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Laboratory samples of reaction-sintered silicon carbide ceramics with permanent adhesive joints were obtained based on isopropyl alcohol and phenol-formaldehyde resin solutions with different contents of carbide and carbon particles. The joints have the following key structural physical and mechanical characteristics depending on the ratio of the phase components formed in the volumetric joining zone: thickness of the silicon layer in the seam is 20…130 ?m, flexural strength is 40…250 MPa, longitudinal sound velocity is 10 750…11 300 m/s, density is 3.07…3.08 g/cm3. It was experimentally established that varying the content of silicon carbide particles in the adhesive suspension from 20 to 80 % by weight makes it possible to achieve 30…75 % of the strength of the base material of the reaction-sintered silicon carbide ceramics.
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A composite material obtained by ceramic technology from electrofused corundum and finely dispersed glass is used to simulate the formation of the pore space of a porous ceramic material. According to the rate of free water saturation, the ratio of volumes of through and dead-end pores in samples obtained from powders of different granulometric composition at different sintering temperatures was estimated. For samples of composites with an open porosity of 36…50 %, the size of the pore channels was estimated using capillary porometry. The correlation between the average pore size and the granulometric composition of the powders used in the production of composite materials is demonstrated.
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Radiation-resistant glass of the K-208 brand has been used for a long time as a protective coating for solar panels and thermoregulating coatings (TPMS) of spacecraft in the form of thin plates with a thickness of 100...200 microns. The methods of cleaning the surface of protective coatings in the form of glass tape and nozzles for the manufacture of glass elements of TRP are compared and the advantages of the method of laser cleaning of their surface are formulated.
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An overview of the applications of zirconium dioxide, partially stabilized with yttrium oxide, in various high-tech fields is presented. Particular attention is paid to its use in supercapacitors, where this material significantly increases the stability of devices during long-term cyclic tests, which is critically important for their practical application. In the field of solid oxide fuel cells, zirconium dioxide, partially stabilized with yttrium oxide, demonstrates exceptional characteristics, acting as an electrolyte, anode and membranes. When operating in the temperature range of 800...1000 °C, the material provides high ionic oxygen conductivity, which directly affects the efficiency of the entire fuel cell. In microelectronics, zirconium dioxide stabilized with yttrium oxide is used in the manufacture of thin-film transistors, where its outstanding dielectric properties and thermal stability become determining factors. This allows you to create reliable and high-performance electronic components. In the aviation industry and the production of gas turbine engines, zirconium dioxide, partially stabilized with yttrium oxide, is used as a heat-protective coating for hot path parts. The material demonstrates excellent resistance to extreme temperature loads, making it an ideal solution for protecting critical components. Various methods of applying such coatings, including plasma spraying and chemical deposition from the gas phase, are considered, as well as a detailed analysis of their characteristics, including layering, porosity, crystal structure of coatings and their thermal stability.
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The article briefly describes the history of cooperation between the Glass and Ceramics magazine and the Department of Chemical Technology of Ceramics and Refractories at the Mendeleev University of Chemical Technology, which has been ongoing for over 90 years.
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The article is a brief excursion into the history of long-term interaction of the “Glass and Ceramics” journal and the department of chemical technology of glass and glass-ceramics at the Mendeleev university of chemical technology.
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The formation of micro-regions with altered refractive index in the volume of float and quartz glasses under the action of single femtosecond pulses has been studied. The phase distributions of the light passing through the micro-regions during observation along the recording direction and perpendicular to it are plotted. The influence of pulse energy on the magnitude of the phase change has been studied. It is established that the minimum energy of formation of micro-regions in the volume of float glass is lower than in quartz glass. The results obtained are of interest for creating analog sound carriers by modifying the glass structure with femtosecond laser pulses.
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The processes of thermochemical hardening of aluminosilicate glass are investigated. The glass was processed in a KNO3 melt under industrial and laboratory conditions at 440…480 °C for 1…120 h. The effect of processing modes on glass properties was evaluated using Vickers microhardness measurement, spectrophotometry, magnetophotoelasticity to measure compressive stresses, and local birefringence analysis to determine the depth of the compressed layer, as well as X-ray fluorescence to evaluate cation exchange. The link between the temperature-time parameters of ion exchange and changes in glass’s structural, mechanical, and optical properties was revealed.
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This paper presents a study of the possibility of synthesizing a thermal insulation material, sludge, based on oil production drilling waste. Samples of drilling mud were collected at the Komsomolskoye oil and gas condensate field and prepared for further use, including drying and milling. Its chemical and phase compositions were determined, confirming the possibility of using the waste for synthesizing thermal insulation materials. A series of raw materials for synthesizing sludge, as well as temperature and time modes of firing, were developed. A study of the physical and chemical properties of the synthesized samples was conducted. The optimal composition for synthesizing sludge was determined, which includes 80 % of drilling mud, 15 % of sodium hydroxide, 5 % of sodium tetraborate, 10 % of water, synthesized at a temperature of 1000 °C and having a density of 745.05 kg/m3.
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Against the backdrop of globally tightened environmental regulations, particularly in the Russian Federation, conventional gas-cleaning methods (cyclones, bag filters, electrostatic precipitators) used in the glass industry are becoming insufficient. These are only effective for capturing suspended particles yet not capable of removing the gaseous marker pollutants at the required level: NOx, SO2, CO. The study is aimed at developing and experimentally validating a highly efficient integrated system that enables 90…95 % removal of gaseous pollutants and approximates 100 % removal of solid particles. A silica/mullite fiber-based reducing catalyst produced entirely from domestic materials (20 cm3) achieved 95 % NO conversion at 350 °C in laboratory reactor tests. The catalytic filter element (with a surface area of 0.02 m2) installed in the pilot setup showed high simultaneous removal efficiencies for multiple pollutants: NOx – 92 %, SO2 – 96 %, at an operating temperature of 380 °C. The authors proposed an integrated purification train that includes an acid-gas neutralization reactor, reagent-dosing systems (for lime, caustic solution, and ammonia water), an inertial separator, a ceramic catalytic filter unit, as well as lime and spent reagent silos. The study was conducted using the Ceramic Pulse-Jet Filter, T Modification, Catalytic Configuration laboratory and pilot testing unit (Bakor R&D Center).
