The electrical conductivity, thermochemical and electrochemical properties of a system consisting of melts of aluminium trichloride and sodium-lithium chlorides taken in different ratios have been studied. In this system, the electrochemical behaviour of Ni2+ ions via cyclic voltammetry and the electromotive force in the modes of heating and cooling of the system were studied. It was found that the melting temperature of the melts passes through a minimum at a lithium chloride (?LiCl) content from 0.23 to 0.35. A possibility of reducing the starting temperature of a nickel-chloride battery with a partial replacement of sodium chloride with lithium chloride is shown, as well as stabilization of its operation at a minimum temperature of 240 °C. An admissibility of using the optimal compositions of the system as an electrolyte in sodium nickel-chloride batteries has been established. It was found that the composition 0.5AlCl3-0.23LiCl-0.27NaCl has a minimum melting point (111 °C), a minimum activation energy for conductivity (8.9 kJ·mol-1), and a sufficiently high electrical conductivity (0.53 S·cm-1 at 250 °C).

The impact of the inside erosion of a microelectrode on the cooling medium motion is considered in the paper. Taking into account the equation of continuity for a fluid flow inside the microelectrode cannel, the analytical relation between the pressure gradient flow and the number of defects (holes and cavities) of the internal cooling surface is received. Driven by this ratio, the method of a early detection of the defect nucleation and the defect dynamics inside the microelectrode cannel is proposed, and a simple analytical motion model for the cooling medium is build. The motion variables are evaluated, and an effective way to remove the soil particles from the erosion area by a medium flowing is offer. The findings are in good agreement with the studies elsewhere and experimental data of other researchers.

The volume of the discharge chamber has a great influence on the pressure field in the water filling it and on the efficiency of many technological processes; therefore, the study of the relationship between the volume of the chamber and the pressure in it is an urgent task. However, at present, the role of the volume of the discharge chamber in the formation of the pressure field in it has been insufficiently studied. The purpose of this work is to fill the gap. The study was carried out on the base of a previously developed mathematical model of an electric discharge in water, the adequacy of which was substantiated via a comparison of the simulation results with experimental data. It is determined that the closed volume of the discharge chamber with rigid walls significantly affects the formation of the pressure field in the water filling it. In this case, the interaction of waves reflected from the walls of the discharge chamber with the surface of the discharge channel in water and the vapor-gas cavity is of decisive importance. The reflected waves determine the period and amplitude of the pulsation of the discharge channel and the vapor-gas cavity, thereby influencing the electrical characteristics of the discharge. This influence increases with decreasing the chamber volume.

It is shown that at high-speed pulsed galvanostatic anodic dissolution of chromium-nickel steels Kh3N35VT (CSN17335), Kh18N10 (AIS1 304) in the regions of pulse durations of 20–2000 ms and current densities of 1–100 A/cm2 in electrolytes for their electrochemical dimensional machining (ECDM) (chloride, nitrate, and mixed chloride-nitrate with an electrical conductivity of 0.15 S/cm), a significant part of the charge (up to 50%) is spent on the formation of a passivating oxide film having a semiconductor character. As a result, the film, not the alloy, is subject to electrochemical treatment. As a result, the current output of the ECDM process of these materials under pulsed conditions is ~ 50–70%, depending on the composition of the alloy. The speed of the process increases with the transition to a constant processing current because of the destruction of the film due to its thermokinetic instability (“thermal explosion”) caused by an increase in the surface temperature.

By the methods of mathematical three-dimensional modeling, the features of the distribution of electric and thermal fields in the volume of the molten alloy of the foundry hypoeutectic silumin A356, when it is treated with an electric current by parallel electrodes, are established. It was found that the geometry of the electrode system qualitatively and quantitatively determines the effect of the electrothermal effect on the melt by the treatment of the direct current. It was demonstrated that the depth of the deepening of electrodes with a non-insulated lateral surface does not have an active influence on the temperature processes during the conduction electric current treatment. The obtained qualitative and quantitative data for the systems with non-insulated electrodes correspond to the experimental data. It is shown that a change in the spatial geometry of the arrangement of electrodes with an isolated lateral surface significantly affects the three-dimensional distribution of electric and thermal fields as well as the quantitative, more than thrice, change in the characteristics of these fields in the volume of the melt. The method of controlling of the conductive electric current treatment of melts, based on the spatial change of the type of electrode system, does not require additional financial costs and can be carried out directly during the treatment.

The one-stage electrohydrodynamic (EHD) pumps with electrodes “a diaphragm – a plate with a hole” and “a wire – a plate with a hole” are studied. It is established that with the help of flow-limiting diaphragms, the pump characteristics can be significantly improved. It is indicated that in the main multi-stage EHD pumps, it is preferable to use lattice-type electrodes made of bare and perforated insulated wires. Optimal geometrical parameters of electrodes, flow-limiting diaphragms, dielectric coatings, and interelectrode distances are determined. The influence of the electrophysical properties of the working medium and galvanically isolated high voltage sources on the performance of a multistage pump is considered. Possible ways to reduce the mutual influence of steps on its output parameters are shown. Formulas have been obtained that reliably fully reflect the physical nature of the results of studies of the characteristics of EHD pumps. It was found out that organosilicon liquid has the best characteristics and considering the stability of its properties under the influence of an electric field, micro-discharges, and temperature, it is recommended to use it as a coolant in EHD heat exchangers. The reasons for the deterioration of the pump characteristics during prolonged operation are identified, and ways to reduce the influence of these factors on the output parameters are noted.

The analysis of the results of experimental studies of the influence of changes in the initial conditions on the energy characteristics of a controlled high-voltage electrochemical explosion (HVECE) is carried out, the main factors affecting the specific energy efficiency of chemical transformations of a water-filled exothermic medium (WFEM) in its discharge channel are determined. The range of rational changes in the main factors has been established in which an increase in the specific energy efficiency of exothermic transformations of the WFEM in the channel of the controlled HVECE is ensured. This will make it possible to reduce the weight and size characteristics and power consumption of the pulse current generator to ensure the necessary energy characteristics of the controlled HVECE, specified by a specific discharge-pulse technology.

To form topology on the surface of semiconductors, halogen-containing plasma, in particular freons, is often used. This article presents a comparative study of the plasma-chemical interaction of R-23 freon with the semiconductors surface by the atomic-force microscopy; silicon and gallium arsenide in terms of purity and uniformity of the process. Freon R-23 is widely used in the technology of industrial etching of Si, Ge, and a number of other materials, providing acceptable rates of interaction while maintaining a uniform surface suitable for further operations of the technological cycle.