The paper presents a model of metal powder melt impregnation under low-frequency vibration in the form of mathematical dependencies. The effect of such factors as powder size, powder wetting with a melt, melt viscosity, conditions and parameters of vibration treatment on the impregnation degree is considered. The simulation results are supported by the experimental data obtained with the use of a vibration treatment and without it. The paper formulates recommendations on the selection of amplitude-frequency parameters.

The paper studies the structure and basic physical and chemical properties of titanate dysprosium powders produced by mechanochemical synthesis from the low-temperature modification of titanium oxide and modification of dysprosium oxide using X-ray diffraction methods (XRD), scanning electron microscopy, Raman spectroscopy (Raman spectra), transmission electron microscopy, and chemical analyz. Based on XRD it was found that complete conversion of initial oxides into X-ray amorphous dysprosium titanate (Dy₂TiO₅) occurs during mechanical treatment of the mixture for 30–60 min. Microelectron-diffraction pattern of Dy₂TiO₅ powders produced by mechanical synthesis has a ring-shaped structure with a certain amount of crystalline phase inclusions, which is typical for an X-ray amorphous phase. Dysprosium titanate powder produced by the induction melting method has a regular cubical lattice with a parameter 3,4 Å.

The structure and mechanical properties of Al–Sn composites produced by vacuum liquid-phase sintering of a mixture of aluminum (ASD-4) and tin (PО2) powders were studied. Sintering of raw briquettes with a porosity of ~15 % was carried out at a temperature of 570–620°C and a holding time of 0,5 to 2,0 hours. The tin concentration in briquettes was increased by step of 10 wt.% and reached 50 wt.%. It was found that the liquid-phase sintering method makes it possible to produce composites with a high second phase content and a continuous Al-matrix capable to prevent localization of deformation in layers of soft Sn-phase under external loading. The optimal composite sintering mode corresponds to a holding time of 1 hour at a temperature of 600 °C. The increase of tin proportion leads to a decrease of the aluminum matrix binding, wherein the matrix remains continuous when the tin content does not exceed 50 wt.% (27 vol.%). Evaluation of mechanical properties of sintered materials was carried out by the compression test. The strength of produced sintered composite materials (CM) is described by an ideal mixture formula: σКМ = σAlfAl + σSnfSn, where σSn is a constant, because tin is not hardened, and σAl value is determined by the compression curve of pure aluminum.

The paper is dedicated to the study of kinetics and combustion mechanism of reaction mixtures in Zr–Si–B and Zr–B systems, production of compact ceramic materials in a process of SHS compaction, as well as studying their heat resistance. The paper demonstrates that temperature and combustion speed dependencies of compounds in the Zr–Si–B system on the initial temperature (T₀) are linear, i.e. with a rise in T₀, staging of chemical reactions of zirconium diboride and disilicide formation does not change. The paper calculates values of the effective SHS process activation energy, which demonstrate the crucial role of the reaction interaction between zirconium and boron and silicon in a melt. The paper studies the staging of chemical reactions in a mixture Zr–Si–B combustion wave: initially, the ZrB₂ phase is formed from the melt by crystallization, then the ZrSi₂ phase appears with a delay of 0,5 s and 1 second later unreacted Si crystallizes. The paper studies the phase composition of synthesis products with diboride ZrB₂ as a main component and zirconium disilicide ZrSi₂, Si and boride ZrB₁₂ depending on the initial reaction charge composition. The new compact samples characterized by high hardness and low residual porosity were produced in the process of power SHS compaction. Formation of oxide films SiO₂–ZrO₂–B₂O₃ along with the complex oxide ZrSiO₄, which serve as an effective diffusion barrier and reduce the oxidation rate, occurs on the surface of SHS-samples in response to their high-temperature oxidation and depending on their composition.

This work aims to produce biocompatible ceramic materials in the Ti–C–Co–Ca₃(PO₄)₂–Ag–Mg system by a combustion mode synthesis. The work studies the effect of cobalt on the parameters of mixture combustion, the structure and properties of resulting products. Compact ceramics consist of a combined non-stoichiometric titanium carbide (TiC_0,5–TiC_0,6) grain frame with a titanium phosphate phase (Ti₃PO_x) evenly distributed along the grain boundaries and local formation of calcium oxide (CaO). The introduction of cobalt leads to formation of the complex phosphide CoTiP and intermetallic TiCo. Silver and magnesium doping leads to formation of a solid silver-based solution.

Tungsten deposition from a gaseous mixture of tungsten hexafluoride and hydrogen on the surface of a porous preform made of thoriated tungsten makes it possible to bond particles of peripheral layers and its core against each other, and create more plastic surface coating capable of relaxing stresses occurring during rotary forging, thus preventing destruction of semi-finished products. The described method made it possible to carry out rotary forging of the pilot batch consisting of insufficiently sintered preforms of thoriated tungsten which were previously destroyed if processed uncoated. The achieved improvement of technological properties may be used in the production of similar tungsten-based compositions (grade VL and VI), as well as for other types of deformation. The results can be applicable for the following: 1) Lowering the sintering-welding temperature of bars (and rods) made of dispersion-strengthened tungsten-based compositions, thus reducing power consumption and increasing the time between equipment overhauls; 2) Increasing the size of semi-finished products produced with the existing equipment, thus increasing the process productivity and expanding the range of output products; 3) Releasing less environmentally hazardous thoriated tungsten products, thus greatly reducing radiation exposure of operators; 4) Using composite cathodes in arc xenon lamps, thus increasing their operational life by 2–3 times.

The paper presents the results of predictive calculation of boron silicide thermodynamic properties (enthalpy, entropy, heat capacity) required for the thermodynamic analysis of the Si–B–Cl–H system conducted by means of the TERRA software. The paper considers cases of SiB4 and SiB6 condensed phase formation in the reaction mixture. The chemical vapor deposition parameters (temperature, pressure, the ratio of initial reagents) of silicon borides were evaluated by thermodynamic calculations of the Si–B–Cl–H system formed by the SiCl₄, BCl₃, and H₂ for a temperature range of 1000–2200 K and a pressure range of 0,00001–0,1 MPa. The paper demonstrates that thermodynamic stability of higher chlorides in the Si–B–Cl system decreases with decrease in pressure, while the proportion of lower chlorides increases, i.e. degradation of initial silicon and boron chlorides occurs, but condensed phases SiB₄ and SiB₆ do not form – their appearance is facilitated by hydrogen introduction. It was determined that both single-phase and multiphase coatings can be produced by varying the chemical vapor deposition parameters. The results obtained in this paper are of scientific and practical interest for the developers of various silicon boride production processes (gas phase, liquid phase, etc.).

The paper demonstrates the possibility of using Next100 type binders alloyed with nickel and modified with WC, ZrO₂ and hBN nanoparticles for the manufacture of cutting tools based on superhard materials intended for steel and cast iron machining. It was found that nickel alloying of the binder makes it possible to increase its impact strength by 2,5 times and significantly improve the life of tool segments while in operation. Introduction of WC, ZrO₂ and hBN nanoparticles into the binder increases its strength by 100–150 MPa and hardness by 5–7 HRB. In the presence of WC nanoparticles, the adhesion of cubic boron nitride to the binder increases. The optimal ratio of diamond to CBN grains in the coating is determined for better tool performance – 75 : 25. The paper reveals the formation of amorphous boron nanoclusters at the at CBN-binder interface, and dissolution of a small amount of nitrogen in the binder components during hot pressing.