Copper-matrix composites reinforced with TiC grains and containing graphite particles were fabricated by self-propagating high-temperature synthesis (SHS) of titanium carbide followed by infiltration of a Cu–Ti melt into a hot TiC–graphite skeleton. The samples were produced by pressing powder mixtures into bilayer cylindrical compacts: the upper layer consisted of Cu + Ti, while the lower layer contained (Ti + C) + graphite. During heating, combustion was initiated in the lower layer, resulting in the formation of porous titanium carbide and its subsequent infiltration by the Cu–Ti melt from the upper layer. As a result of SHS infiltration, TiC–C–Cu(Ti) composites were obtained. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectro­scopy (EDS) revealed that variation in the Ti content of the Cu melt significantly affect the composite structure, leading to heterogeneity of the metallic matrix composition and changes in the morphology of TiC particles. Titanium carbide formed as polyhed­ral particles, indicating its non-stoichiometric composition (Ti:C ≈ 1:0.7÷1:0.4) as a result of the interaction between titaniumi dissolved in the melt and previously formed TiC. In addition, the Cu–Ti melt reacted with graphite particles, forming a layer of TiC at the interface. The presence of titanium in copper therefore promotes chemical interaction between the copper melt and the TiC–C skeleton, ensuring good wetting and spontaneous infiltration of the Cu–Ti melt into the SHS-derived TiC–C skeleton. The Cu–Ti matrix exhi­bited a hardness of up to 55.1 HRC, which is attributed to solid-solution strengthening by titanium dissolved in copper.

The main patterns of structure formation and phase composition of Fe–Ti materials promising for hydrogen storage were investigated during explosive compaction of titanium–iron powder mixtures followed by sintering of the resulting compacts at elevated temperatures. It was established that explosive compaction of Ti + Fe powder mixtures makes it possible to obtain materials consisting of titanium and iron grains with virtually zero porosity and a developed contact surface between particles, which creates favorable conditions for interphase interaction between them during subsequent heating. Heating such materials to 1100 °C with a 1-h hold results in the formation of a liquid phase and the precipitation of TiFe and Ti₂Fe intermetallic phases in the melt. After cooling, this leads to the formation of either a TiFe + Ti₂Fe structure (with Ti content of 57– 59 at. %) or a TiFe + Ti₂Fe + β-Ti (59–68 at. % Ti) The hydrogen sorption properties of the obtained materials during electrochemical hydrogenation were studied. It was shown that the presence of accompanying phases (the β-solid solution of iron in titanium and metastable Ti₂Fe intermetallic) in the structure, together with the TiFe intermetallic compound, eliminates the need for preliminary activation and leads to a significant increase in hydrogen capacity during primary hydrogenation. Materials of the Ti–Fe system with increased titanium content were found to retain their ability for reversible hydrogenation up to a titanium content of 67 at. %. The highest reversible hydrogen capacity was achieved at 64 at. % Ti and reached 2.16 wt. % H, which significantly exceeds the capacity of conventional Ti–Fe materials currently in use. The ratio of TiFe and Ti₂Fe phases in the material structure is close to 1:1.

Metal-matrix composites Ti13Nb13Zr/(Ti,Nb)B and Ti18Nb8Zr/(Ti,Nb)B were produced by vacuum arc remelting; the TiB₂ content in the initial charge was 0.7 and 2.0 wt. %. Unreinforced Ti13Nb13Zr and Ti18Nb8Zr alloys produced by the same method were used for comparison. The structures of unreinforced alloys consists of acicular α-martensite fromed by submicron-thick laths located in a β matrix. The microstructure of the cast composites consisted of similar two-phase α + β matrices of Ti13Nb13Zr and Ti18Nb8Zr and numerous (Ti,Nb)B boride fibers randomly distributed in the matrices. The unreinforced Ti13Nb13Zr alloy exhibited a yield strength of σ_0.2 = 600 MPa and an elongation of δ = 21 %. The Ti13Nb13Zr/(Ti,Nb)B composites containing 0.7 and 2.0 wt. % TiB₂ in the initial charge showed an increase in yield strength to 620 and 730 MPa and a decrease in elongation to 3.6 and 0.5 %, respectively. For the unreinforced Ti18Nb8Zr alloy,  σ_0.2 = 560 MPa and δ = 15 % were obtained. The addition of 0.7 and 2.0 wt. % TiB₂ to the Ti18Nb8Zr alloy matrix increased the yield strength to 610 and 700 MPa and reduced elongation to 6.0 and 0.3 %, respectively. It was established that reinforcing Ti13Nb13Zr and Ti18Nb8Zr alloys with borides, regardless of their concentration, improves corrosion resistance of these materials. Investigation of the tribological properties revealed a high level of wear resistance for the Ti13Nb13Zr/(Ti,Nb)B and Ti18Nb8Zr/(Ti,Nb)B composites.

Ultrafine-grained (UFG) ceramic materials exhibit improved reliability compared with coarse-grained ceramics due to the higher density of grain boundaries. This increases the crack propagation path during intergranular fracture, which is particularly beneficial for composite materials where intergranular fracture typically dominates. The formation of a UFG structure requires a detailed understanding of the sintering behavior and grain growth mechanisms in ceramic materials. In this study, submicron single-phase powders (150–350 nm) of binary and high-entropy carbides (HECs) of stoichiometric (C/Me = 1) and non-stoichiometric (C/Me = 0.8) compositions were obtained by the calcium-carbothermic synthesis. The powders were  consolidated by spark plasma sintering (SPS) at temperatures of 1350–1950 °C with holding times of 0–20 min. The effect of SPS temperature and powder stoichiometry on grain growth, sintering shrinkage, and the activation energy of sintering and grain coarsening was investigated. The behavior of high-entropy carbides was compared with that of tantalum carbide. The results show that carbide stoichiometry  significantly affects sintering behavior. A decrease in stoichiometry, corresponding to an increased concentration of carbon vacancies, reduces the activation energy of sintering and grain coarsening and increases the shrinkage rate. The onset of grain growth was found to be independent of stoichiometry and occurs at a relative  density of ~0.90÷0.95. In highly dense ceramics (>0.95), grain growth proceeds most intensively in stoichiometric carbides, which is observed both in HECs and in TaC.

This study is aimed at the development and characterization of Co–Cr–Fe–Ni powder alloys strengthened with WC or ZrO₂ nanoparticles. Compact specimens were produced by mechanical alloying of an equiatomic mixture of Co, Cr, Fe, and Ni powders with the addition of 0.5–2.0 vol. % WC or ZrO₂, followed by hot pressing. XRD analysis confirmed the formation of a single-phase FCC structure, whereas SEM and EDS revealed a uniform distribution of the strengthening particles within the matrix. The best mechanical properties were obtained for the following compositions: (CoCrFeNi) + 1 vol. % WC (hardness 73 HRA, ultimate tensile strength σ_tens = 1292 MPa and bending strength σ_bend = 2267 MPa), (CoCrFeNi) + 1 vol. % ZrO₂ (72.5 HRA, σ_tens = 1360 MPa), and (CoCrFeNi) + 2 vol. % ZrO₂ (σ_bend = 2285 MPa). The strength of the investigated alloys was several times higher than that of powder alloys (CoCrFeNi)_100–xTi_x (x = 4÷12 at. %), which were dispersion-strengthened by secondary phases. The maximum ductility (elongation δ = 2.3 % for (CoCrFeNi) + 0.5 vol. % ZrO₂) exceeded that of Ti-containing analogues by an order of magnitude but was significantly lower than that of unreinforced CoCrFeNi alloys (δ = 56÷88 %). Tribological tests revealed the advantages of the alloy containing 1 vol. % WC, which exhibited the lowest wear rate (0.96·10^–4 mm³/(N·m)) and friction coefficient (μ = 0.69) due to the formation of a stable tribolayer. ZrO₂-containing alloys showed higher wear rates ((2.20–2.22)·10^–4 mm³/(N·m)) and a higher friction coefficient (μ = 0.78) as a result of brittle fracture of the ceramic phase. The properties of the (CoCrFeNi) + 1 vol. % WC alloy make it suitable for applications requiring high strength and wear resistance, whereas ZrO₂-containing alloys require further modification to improve their performance.

The influence of substrate material – cemented carbide (WC–Co containing 6 wt. % Co) and high-speed steels R18 (Russia), T1 (USA), and HS18–0–1 (Germany) – on the properties of strengthening Arc-PVD Ti–Mo–Al–Si–Ni–N coatings was investigated. Coatings deposited on high-speed steel substrates exhibited lower hardness, adhesion strength, and wear resistance than those depo­sited on cemented carbide substrate. This behavior is attributed to a reduction in compressive residual macrostresses compared with coatings on the cemented carbide substrate. The decrease in compressive stresses is associated with local overheating of the coating during deposition. Under ion bombardment, heat removal from the coating growth zone occurs more slowly, which promotes relaxa­tion of internal stresses. This effect is caused by the lower thermal diffusivity of high-speed steel compared with cemented carbide. Numerical simulation of substrate and coating heating during deposition confirms this mechanism.

Using a combination of methods including low-temperature nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and others, the particle size distribution and morphology of amorphous boron, vanadium pentoxide, and boron modified with 2 wt. % vanadium pentoxide were investigated. The adsorption isotherms were analyzed in terms of their correspondence to the Bru­nau­­er – Deming – Deming – Teller (BDDT) classification and to the corresponding type of porosity, which is important for determining the potential application areas of the powders. It is shown that the type of chemical bonding in the adsorbent, its structure, and the features of surface formation during modification influence the adsorption and structural characteristics of the synthesized sample and allow its textural parameters to be controlled.

The possibility of forming coatings on a of C/C–SiC composite substrate by slurry painting followed by in situ reactive firing of MoSi₂–HfB₂–Si, MoSi₂–HfSi₂–HfB₂–SiB₄ and MoSi₂–HfSi₂–SiB₄ powder compositions at 1620 °C and an argon pressure of ~100 Pa was investigated. The resulting coatings exhibit a framework structure formed mainly by fragmentarily sintered MoSi₂ grains with uniformly distributed HfB₂ particles between them. The synthesized HfB₂ particles have a polyhedral morphology with sizes of 5 to 10 μm and also form nanowhiskers 100–200 nm thick and 2–4 μm long. A sequence of reactions occurring in the MoSi₂–HfSi₂–HfB₂–SiB₄ and MoSi₂–HfSi₂–SiB₄ systems is proposed, which determines the in situ synthesis of secondary HfB₂ and SiC phases. It was established that grain sintering occurs only fragmentarily and proceeds predominantly by a liquid-phase mechanism, as indicated by the presence of numerous highly compact fragments in the structure (especially in the MoSi₂–HfSi₂–SiB₄ system). However, the fraction of the transient liquid phase in both systems is insufficient to obtain coatings with the required high structural continuity throughout the volume. Physicochemical calculations were carried out for the investigated systems. It is shown that, depending on the composition, the total porosity of the coatings is approximately 53–57 %. Silicon evaporation and pyrolysis of the organic binder during heat treatment make the greatest contribution to the formation of discontinuities, producing porosity of 29–37 and 20–25 %, respectively. Promising approaches to reducing the porosity of coatings formed by this technology are identified.