The dispersed composition and morphology of the particles of metal powders of the composition Al–1,5%Ca–1,5%La before and after interaction with water are investigated using a complex of methods including low-temperature nitrogen adsorption, scanning electron microscopy, X-ray phase analysis, etc. It is shown that the treatment of this metallic powder with water leads to the formation of slit-like and cylindrical pores in interaction products. The specific surface increases from 9 to 182 m²/g in this case. It is confirmed by the X-ray phase analysis that thermal treatment of aluminum powders right up to 200 °C leads to the formation of the particles of gel-like boehmite AlOOH on the surface. The results of investigations showed that hydrotreating allows one to vary the texture characteristics of ultradispersed powder.

The influence of dispersed microadditives of different nature on bulk changes during sintering and strength of powder carbon and high-chromium steel is investigated. Mechanisms of the influence of additives on their structure formation are described. It is shown that the largest hardening of carbon steel is provided by the introduction of sodium bicarbonate, while of high-chromium steel – of boron nitride additives. The level of hardness increase depends on the sintering temperature and additive amount.

The results of the investigation into compacting (sintering) in high-pressure apparatus of the DO-138 model of nanopowders and micropowders of silicon carbide are presented. Compacting modes for both types of materials were identical (pressure of 3.5–4.0 GPa, temperature of 1600–1700 °C, and holding time of 10 s). The influence of cladding the SiC nanopowders and micropowders with titanium and titanium nitride on the properties of compacts (cakes) fabricated in the same sintering modes is also considered. It is established that when compacting the silicon carbide nanopowder, the formed cakes differ by the higher density, hardness, and lower porosity compared with the samples of finely dispersed silicon carbide of technical grade. High activity of titanium with respect to SiC allows one to bond chemically the grains of the latter due to the formation of intermediate layers of titanium compounds between them. This is resulted in that the formed ceramics possesses high density, hardness, and wear resistance. Wear resistance of synthesized composites based on nano-SiC is higher by a factor of 4.5 than that one of polycrystalline material made of silicon carbide micropowder.

The experiments on the preparation of materials based on Ti–3Al–0,5Ta and 3Ti–2Al–Ta systems by self-propagating high-temperature synthesis (SHS) are performed. The influence of the composition of the initial mixture, dispersity of powders, and preliminary mechanical activation on the phase composition and structure of the SHS product are investigated. The optimal ratio of mechanically activated and initial powders in the mixture for the synthesis of materials is determined. The dependence of the structure of final products on the structure of initial powders is established. The use of porous tantalum leads to the formation of the intermetallic matrix based on titanium aluminide with the uniform distribution of Ta particles. It should be noted that tantalum powders of both series under study (which differ by dispersity and morphology) partially reacted already at the stage of mechanical activation with the formation of the Al₂Ta phase. It is shown that aluminum plays the leading role in mechanical activation processes in Ti–Al–Ta reaction mixtures. Indeed, as the amount of aluminum in the reaction mixture decreases, a considerable rise of unreacted tantalum particles in the microstructure of synthesized samples is observed.

Kinetic features and mechanism of contact interaction of hot-pressed (residual porosity <3 %) samples of titanium carbonitride samples of various compositions with the Ni–25%Mo melt (t = 1400¸1500 °C, t = 0,1¸25 h) are for the first time systematically investigated by the electron probe microanalysis. It is established that the dissolution rate of the refractory interstitial phase (RIP) in the Ni–Mo melt decreases in a series TiC–TiC_0,7Ni_0,3–TiC_0,5Ni_0,5, while the degree of incongruence of the process rises. The composition of intermediate interaction products varies correspondingly. Formation mechanisms of the most important phase component of TiCN cermets—the K-phase (double carbide of the Ti_1–nMo_nC_x composition)—are revealed. It is proven by local mass-spectrometry that the K-phase has a carbide nature. It is also established that it is formed only if titanium carbonitride TiC_1–xN_x is sufficiently enriched with carbon (x £ 0,5). It is stated that the K-phase is in fact the base of all cermets with the Ni–Mo binder. Its bulk concentration in alloys exceeds the nominal alloy-base content by several times. The chemical substantiation of the selection of titanium carbonitride of the TiC_0,5N_0,5 composition as the optimal «precursor» of the K-phase, which is formed during the liquid-phase sintering of TiCN cermets, is given for the first time.

The structure of interphase boundaries in hard alloys fabricated by explosive compacting of the powder mixture of chromium carbide (Cr₃C₂) and titanium is investigated. It is established by electron microscopy that these boundaries have a thickness of the order of 100 nm, along which, a smooth variation in the chromium and titanium content with the almost constant carbon content is observed. The structure of boundaries is nonuniform over the thickness: a layer 5–7 nm thick with an amorphous structure is detected between two crystalline interlayers. It is shown that these layers are the layers of specific «boundary phases» matching none phases of the equilibrium phase diagram of the Cr–C–Ti system.

The review of publications of domestic and foreign authors devoted to the influence of additives of tantalum carbide on the properties of hard alloys of the VK group is presented. The structure, properties, application regions, and advantages and disadvantages of TaC-alloyed hard alloys are analyzed and main technologies of their fabrication are considered. The positive influence of additives of 1–3 % TaC coatings on the properties of WC–Co alloys, which allows one to elevate the operational characteristics of the cutting, stamping, and drilling tool, is shown. It is noted that the interest to the investigation into the influence of tantalum carbide on the properties, structure, and nature of this phenomenon does not weaken to date, while its mechanisms are not known completely.

The composition and thermodynamic characteristics of plasma-forming gases (Ar, N₂, H₂, and mixtures Ar + N₂ and Ar + H₂) depending on temperature are investigated using the thermodynamic simulation procedure. The equilibrium composition and thermodynamic properties of the plasma–«particle» system are modeled. Pure metals, oxides, manufacturing powders, and powder mixtures are considered as the particle. The influence of powder materials TiO₂, Al₂O₃, and Fe₂O₃ on the variation in the heat content of plasma is investigated.

The electrochemical deposition of coatings of double tungsten and molybdenum carbides from tungstate–molybdate–carbonate melts is investigated. The composition of fabricated coatings is investigated by X-ray fluorescent and X-ray phase analyses; crystal sizes and coating thicknesses are determined using scanning electron microscopy. Optimal deposition parameters of coatings W₂C–Mo₂C are established: the melt composition is Na₂WO₄–(1,0¸4,0 mol.%) LiW₂O₄–(1,0¸4,0 mol.%) Li₂MoO₄–(1,0¸5,0 mol.%) Li₂CO₃, the cathode current density is 750–1500 A/m², the process temperature is 1123–1173 K, and the electrolysis duration is 4 h.

Electric-discharge coatings on the samples made of steel 30ХГСА fabricated using a UR-121 installation are investigated. Electrodes for electric-discharge machining are fabricated by hot compacting from the powders prepared by electroerosive dispersing of waste of high-speed steel Р6М5. The microstructure, thickness of the coating layer, and its surface state are studied using modern investigation techniques. Roughness parameters of wares and microhardness of the electric-discharge coating and substrate made of steel 30KhGSA are determined. It is established that the coating microhardness is larger than that one of the substrate by a factor of 2,1, which can be associated with a nonuniform distribution of the particles of high-speed steel in the electric-discharge coating. It is shown that powder materials fabricated by electroerosion dispersing from high-speed steel wastes can be used as the electrode material to fabricate various functional coatings by electric-discharge alloying.

Problems of applying the diamond-like coatings (DLC) on steel parts of pumps for the petroleum industry are discussed. The main accent is made on the review of the ways for increasing the adhesion of coatings and analysis of the causes of destruction of diamond-like and other superhard coatings in water-containing and abrasive-containing media. The main cause of destruction of DLCs on the parts in water-containing media during the abrasive wear is the catastrophic adhesion lowering upon the water ingress on the substrate–coating interface. To fabricate the relatively thick protective DLCs, the search for the ways of increasing adhesion and lowering internal stresses is necessary. The data on limiting loads (L_с) during the tests of DLCs by scratching depending on their fabrication technology, coating thickness, presence of intermediate layers, and preparation techniques of the substrate surface are presented. Examples of attaining high values of L_с due to applying special methods of chemicothermal treatment of steel substrates are shown.