VOL 99, No. 3 (2026)

It is known that the introduction of small Na2O additives (up to 5 mol. %) into the glass composition of the ZnO–MgO–Al2O3–SiO2 (ZMAS) does not interfere with the production of zinc spinel (ZnAl2O4) based glass-ceramic and allows the usage of ion exchange for further improve their mechanical properties. In this work, the submicrostructure of ZMAS glass-ceramic with sodium oxide additives in a transparent state and at the initial stages of opalescence and opacity was studied using the TEM method using XRD data. The main crystalline phase, zinc spinel, embedded in the glass-ceramic, does not contain sodium cations: they remain in the residual glass phase, creating favorable conditions for the strengthening of the material by ion exchange. After heat treatment of glass for 10 h in the temperature range 770…790 °C, in addition to zinc spinel, zinc-magnesium silicate (Zn, Mg)2SiO4 crystallizes, the particle sizes of which reach 15…20 nm, while the sizes of ZnAl2O4 crystals do not exceed 6 nm, and therefore it is the silicate phase that limits the conditions of crystallization and prevents the improvement of strength properties and preservation of transparency.

Ceramic materials based on silicon carbide were synthesized using reaction sintering with the introduction of a reactive component – technical carbon black – into the starting mixture at varying concentrations (5, 15, and 30 % by weight). The tribological characteristics of the resulting ceramic materials were determined in a friction pair with a VT6 structural titanium alloy under friction conditions in air and water at room temperature. It was determined that the best antifriction properties (µ = 0.17 in water) are observed during contact interaction between the titanium alloy and silicon carbide material obtained from a mechanical mixture containing the highest amount (30 % by weight) of technical carbon black.

Fe-substituted ceramic materials of the NASICON family, corresponding to the generally accepted formula Na3+yМ(III)yZr2–ySi2PO12, with a dopant concentration from 5 to 20 mol. % were studied. Doping changes the morphology and phase composition of ceramics. Electron paramagnetic resonance spectra indicate the presence of Fe3+ atoms both in the crystalline phase (with g ~ 2.0) and in disordered phases with a strong rhombic component of the crystal field on impurity ions (with g ~4.3 and ~4.2). A quantitative analysis of the distribution of paramagnetic centres in ceramics was performed. It was noted that the dopant is predominantly found in the crystalline phase of the sample. It was shown that Fe-substituted NASICON complexes correspond to the composition Na3М(III)yZr2–ySi2–yP1+yO12. The Fe3+ content in the crystalline phase of these complexes is 36% higher than in samples obtained in accordance with Na3+yМ(III)yZr2–ySi2PO12.

To produce Al–Al2O3 cermet with a heterogeneous granular-layered structure, mixing of flake aluminum powder of the PAP-2 brand with the plasma-chemical alumina powder (PCAP) consisting of nano-thick lamellar agglomerates in a planetary ball mill in the mechanical alloying mode was carried out. The resulting charge, consisting of layered granules containing alternating alumina and aluminum layers, was compacted under a pressure of 700 MPa. Sintering of green samples was carried out in a vacuum (10–5 mm Hg) at a temperature of 650 ? for 1 hour. The content of the alumina component in the cermet composition in the amount of 15% by weight ensured a combination of low density – 2.54 g/cm3 with significant indicators of its mechanical properties (flexural strength – 280 MPa, axial compression strength – 350 MPa, crack resistance – 8.5 MPa?m1/2, microhardness – 1070 MPa) as a result of achieving a compromise between the plasticity of this composite and its hardness. Cermet can be used as lightweight armor protection elements, wear-resistant elements and special abrasive tools.

The adhesion properties of polyurethane- and polyurea-based polymer coatings designed to protect concrete were studied under the climatic conditions of Yakutia. Coated concrete samples were exposed to outdoor conditions for two years, where temperatures ranged from +20 °C in summer to –42.8 °C in winter. The results showed that climatic factors primarily affect the surface layers. During the first year, coating adhesion decreased approximately equally for all samples. However, as the testing period increased, the decrease in adhesion properties became more pronounced and uneven. This is presumably due to moisture absorption by the polymer and concrete, the intensity of which depends on the coating thickness. Freezing of moisture leads to the formation of internal stresses and microcracks, weakening the bond between the coating and concrete. Frequent temperature fluctuations accelerate this process. It was established that the physical and mechanical properties of the coatings are determined by the composition of the original components and the nature of the chemical bonds, while curing temperature has a significant impact on their mechanical characteristics.

This article presents a review of the available scientific and technical information on conductive metallization pastes used in the production by low-temperature co-fired ceramic (LTCC) multilayer electronic components. The influence of the main components of metallization pastes on their rheological properties, sintering temperature, and electrical resistance of the conductive elements of multilayer ceramic boards is examined. It is established that the composition and amount of inorganic and organic components significantly affect the rheological and thixotropic properties of metallization pastes. The size and shape of the metal filler particles have the greatest impact on the sintering temperature and electrical resistance of the conductive elements. The composition and properties of borosilicate glasses and refractory metal oxides in the pastes influence the adhesion of the conductive layer to the glass-ceramic material and the conformity of paste and glass-ceramic shrinkage during the co-firing of the multilayer package.