Basing on the study of the elemental composition of surface composites obtained on 45, 65G, and St3 steels by electrospark alloying using processing electrode from T15K6, VK8 hard alloys, as well as 45 and St3 steels (the “steel on steel” option), it was shown that the resulting surface layers are ~70% composed of the material steel substrate modified by electro-discharge treatment. The influence of the steel composition on the coefficients of the processing electrode material transfer on the substrate, on the roughness, microhardness, and wear resistance of the resulting surfaces has been studied. It is shown that the wear resistance of the resulting composites is determined mainly by the nature of the treated surface and, to a much lesser extent, by the processing electrode material, roughness, and microhardness of the surface.

A possibility of increasing wear resistance of Ti6Al4V alloy after cathodic plasma electrolytic nitriding in a solution of ammonium chloride and ammonia is shown. The competing effect of the surface erosion by the actions of discharges and high-temperature oxidation on the morphology and roughness of the surface was revealed. The complex effect of the surface roughness and surface layer hardness on the wear resistance of the titanium alloy was determined. It was found that the greatest decrease in the weight wear by a factor of 2.7 was observed for the sample with the maximum microhardness of the surface layer, reaching 820 HV, and the smallest surface roughness. It was shown that the friction coefficient decreased in proportion to the treatment time when the surface layer had low hardness, favoring the sliding of the counter-body.

The electrocatalytically active films based on nanodispersed titanium dioxide modified by Y3+ ions and synthesized by the sol-gel method were characterized by the X-ray diffraction (XRD) and ultraviolet-visible photocurrent spectra. Electrocatalytic properties of the TiO2 and Y-TiO2 electrodes were investigated during the process of oxygen electro-reduction. The XRD results indicated that the TiO2 and Y-TiO2 powders with the yttrium content of 0.5–5 mol% calcined at 500 °C had an anatase crystal structure, with the crystallite size of 10–12 nm. The electrodes based on the Y-TiO2 films were photosensitive in a wavelength range of 250–400 nm. For all investigated samples with the Y (III) content of = 5 mol%, both an increase in the photocurrent quantum yield and a shift of spectra towards longer wavelengths vs. those of the undoped TiO2 were observed. The photocurrent quantum yield for the Y-TiO2 samples first increased and then decreased with increasing the Y (III) content, and reached its maximum with 2% Y-TiO2 films. It was found that doping of the TiO2 films by Y (III) improves the catalytic activity of the Y-TiO2 electrodes in the reaction of oxygen electroreduction. A correlation between photo- and electrocatalytic properties and structural changes occurring in the TiO2 films upon yttrium doping has been revealed.

The process of chemical etching of Cu98Be alloy in solutions of various compositions was investigated. The rate of etching of beryllium bronze in the investigated solutions was determined, and its change in time was studied. The selectivity of dissolution of the components of Cu98Be during prolonged etching in solutions of different electrolytes was established. A possibility of achieving uniform etching of Cu98Be alloy by varying the composition of the etching solution was shown. The concentrations of metal ions in the used etching solutions were determined, and the capacity of those solutions was calculated. The compositions of solutions with a high capacity for both alloy components during prolonged etching was established. The optimal compositions of etching solutions providing high-quality etching of beryllium bronze according to several criteria such as: a high process rate, uniform dissolution of alloy components, high capacity for both alloy components were proposed. The morphology of the Cu98Be electrode surface after etching in solutions, providing uniform dissolution for both alloy components, was studied. The absence of surface passivation after chemical etching in these solutions was shown. The chemical nature of the compounds formed in the form of small inclusions on the etched surface of the electrode was established. The obtained results are of great importance in practical use because they allow selecting the appropriate composition of the etching solution, which, in turn, helps to optimize the technological etching process.

????????????? ????????????? ????? ??????????? ??????????? ??????? ???????? ???????????????? ???????? ?? ?? ?????????????????????? ? ????? ?????????, ?? ???????? ???????? ???????? ? ????????? ???????, ??? ??? ??????? ?????? ?????????? ?????. ????????, ??? ??? ?????????????????????? ???????????????? ?????????? ???????? ??? ????????? ?????? ?????????? ?????? ????????, ?????????? ???????????? ?? ????????? ? ???????????? ??????, ????????????? ?? ???? ????? ??? ????? ?????? ? ?????? ?????????? ???????, ?????? ??????? ?????????? ???????? ??????. ? ????? ?? ??????? ??????? ???????? ?? ????? ????????? ??? ?? ??????? ????????????? ?????????? ????? ?????????? ????????????? ????????. ??? ?????? ???????????????? ???????? ????? ???????????????? ???????? ?????????? ???????? ??????? ????? ??????????? ? ???? ????????????? ??????? ???????? ????? ???????????? ??????? ??????? ? ??????????? ?????????? ?? ????????? ? ???????????? ?????? ??????? ? ????? ????????? ??????? ?? ???????????.

The effects of electrical conductivity of magnetic fluids (MFls) are investigated both in the presence and in the absence of an external magnetic field (MF). It is shown that in MFls based on magnetite (Fe3O4) magnetic nanoparticles (MNPs) coated with the surfactant – oleic acid (OA), conductive ions are formed by OA molecules in both dissociation and electrochemical processes. The decisive role of electrochemical reactions of OA molecules on the surface of chemically active Cu electrodes, which form injection conductivity, has been proved. The analysis of the anisotropy of the MFl electrical conductivity in an external MF with chemically active and silent electrodes is given. An interpretation is presented of nonstationary ionic processes in the near-electrode layers which determine the kinetics of MNPs and autowaves in thin layers of MFLs.

The results of an approximate calculation of theaveraged values of speeds of vmz of a longitudinal drift of lone electrons, and of circular frequencies of ?mz change of longitudinal electronic waves de Broglie and of lengths of ?mz of longitudinal electronic waves de Broglie in the metal of round cylindrical conductor with an electric axial-flow current of conductivity of i0(t) of different kinds (permanent, variable, and impulsive) and amplitude-time parameters (ATP). The results of verification of the obtained calculation correlations for speeds of vmz drift of lone electrons and lengths of ?mz of electronic de Broglie waves in the examined conductor demonstrate their validity and working capacity. The obtained data confirm the quantum-wave nature of the electric current of conductivity of the indicated kinds of i0(t) and of ATP in a metallic conductor.

The results of investigations of electrohydrodynamic (EHD) flows using the schlieren method in the following systems of electrodes: “a blade – isolated edge blade”, “a blade – two rods”, and “a rod with a perforated isolation coating – two rods” are presented. On the base of the obtained results, single-stage EHD pumps were designed. Their head and flow specifications were studied depending on various factors. It was shown that the performance of the EHD pumps can be increased by application of dielectric coatings on the electrodes. The maximal efficiency was obtained in the system of electrodes “a blade – a blade with isolated edge”, the maximal static pressure – in a three-rod system with a perforated isolation coating of the emitter. The advantages of a three-rod system were specified related to the improvement of the flow characteristics of the pumps due to their parallel arrangement and increasing of the pump pressure by using multi-stage pumps with grid electrodes.

?? ?????? ???????????? ??????????? ??????? ????????????? ??????????, ?????????? ??????????????? ???????????? ?????? 45, 65? ? ??3 ???????? ???????? ?15?6, ??8, ? ????? ??????? 45 ? ??3 (??????? «????? ?? ?????»), ????????, ??? ???????????? ????????????? ???? ?? ~70% ??????? ?? ????????? ???????? ????????, ???????????????? ???????????????? ??????????. ??????????? ??????? ??????? ????? ?? ???????????? ???????? ????????? ??????????????? ????????? (??) ?? ????????, ?? ?????????????, ?????????????? ? ??????????????? ?????????? ????????????. ????????, ??? ??????????????? ?????????? ???????????? ? ???????? ???????? ?????????????? ??????????? ? ? ??????????? ??????? ??????? ?????????? ??, ?????????????? ? ??????????????? ???????????.