An analysis of common reinforcement methods of machine parts and theoretical bases for the selection of their chemical composition were carried out. Prospects for using flux-cored arc welding (FCAW) to restore and increase the wear resistance of machine parts in industries such as metallurgy, agricultural, wood processing, and oil industry were presented. It is noted that conventional series electrodes made of tungsten carbide are expensive, which limits their widespread use in some industries. The scope of this work includes the development of the chemical composition of tungsten-free hardfacing alloys based on the Fe-Mo-B-C system and hardfacing technology and the investigation of the microstructure and the mechanical properties of the developed hardfacing alloys. The composition of the hardfacing alloys was developed by extending the Fe-Mo-B-C system with Ti and Mn. The determination of wear resistance under abrasion and impact-abrasion wear test conditions and the hardness measurement by means of indentation and SEM analysis of the microstructures was completed. The results obtained show that the use of pure metal powders as starting components for electrodes based on the Fe-Mo-B-C system leads to the formation of a wear-resistant phase Fe(Mo,B)₂ during FCAW. The addition of Ti and Mn results in a significant increase in abrasion and impact-abrasion wear resistance by 1.2 and 1.3 times, respectively.

The prospects of plasma electrolytic oxidation (PEO) technology applied for surface hardening of aluminum alloys are substantiated. The work aims to optimize the technological process of PEO for aluminum in flowing electrolyte. The design of the equipment and the technological process of the PEO for aluminum deformed alloy D16T in flowing silicate–alkaline electrolyte have been developed. Oxide coatings were formed according to various technological parameters of the PEO process. The properties of the oxide coatings were evaluated, respectively, by measurements of coating thickness, geometric dimensions of the samples, microhardness, wear tests, and optical and scanning electron microscopy. To study the influence of the technological parameters of the PEO process of forming oxide coatings on geometrical, physical, and mechanical properties, planning of the experiment was used. According to the results of the conducted experiments, a regression equation of the second order was obtained and the response surfaces were constructed. We determined the optimal values of the technological parameters of the PEO process: component concentration ratio (Na₂SiO₃/KOH), current density, flow rate, and electrolyte temperature, which provide the oxide coating with minimal wear and sufficiently high physical and mechanical properties and indicators of the accuracy of the shape of the parts. The research results showed that the properties of oxide coatings mainly depend on almost all constituent modes of the PEO process. Samples with Al₂O₃ oxide coating were tested during dry friction according to the “ring–ring” scheme. It was established that the temperature in the friction zone of aluminum samples with an oxide coating is lower compared to steel samples without a coating, and this indicates high frictional heat resistance of the oxide coating.

The prospects of using biopolymer nano-containing films for wound healing were substantiated. The main components of biopolymer composites are gelatin, polyvinyl alcohol, glycerin, lactic acid, distilled water, and zinc oxide (ZnO) nanoparticles (NPs). Biopolymer composites were produced according to various technological parameters using a mould with a chrome coating. The therapeutic properties of biopolymer films were evaluated by measuring the diameter of the protective effect. Physico-mechanical properties were studied: elasticity, vapour permeability, degradation time, and swelling. To study the influence of technological parameters of the formation process of therapeutic biopolymer nanofilled films on their therapeutic and physico-mechanical properties, the planning of the experiment was used. According to the results of the experiments, mathematical models of the second-order were built. The optimal values of technological parameters of the process are determined, which provide biopolymer nanofilled films with maximum healing ability (diameter of protective action) and sufficiently high physical and mechanical properties: elasticity, vapour permeability, degradation time and swelling. The research results showed that the healing properties of biopolymer films mainly depend on the content of ZnO NPs. Degradation of these biopolymer films provides dosed drug delivery to the affected area. The products of destruction are carbon dioxide, water, and a small amount of ZnO in the bound state, which indicates the environmental safety of the developed biopolymer film.

This article analyses the problem of automatic balancing rotors with a liquid balancer, which is a cylindrical chamber partially filled liquid of a certain density. This problem is related to the problem of the dynamics of bodies with cavities partially filled with liquid. As part of this task, we analyzed disturbances in the relative motion of the fluid in the ABD chamber caused by the Coriolis force inertia. The distortions of the free surface of the liquid were found, resonant phenomena in the flow of the working fluid were investigated, and the physical explanation of the received results given should be taken into account when designing the corresponding ones self-balancing devices. It was established that the axial component of the Coriolis inertial force causes peculiar wave phenomena in the correcting fluid movement. For the given nature of undisturbed motion, the conditions of this phenomenon’s occurrence are determined only by the geometric dimensions of the cylindrical chamber and the thickness of the liquid layer in undisturbed motion, and do not depend on the intensity of rotation of the liquid, nor on its density. It is shown that a decrease in the “ABD chamber height–radius” ratio leads to stabilization of the movement of the system. Experimental verification has been performed; theoretical results on the developed stand for work research rotor system with a vertical axis of rotation.

In this study, three conceptual designs of bracket constructions made of aluminum alloy underwent numerical investigation. To analyze the von Mises stresses present throughout the entire structure, the Ansys program was employed in conjunction with the static structure tool. The selection criteria are determined by two primary elements. The first element is the performance of the design, represented by normal stresses and deformation resulting from the applied load. The second criterion is volume, dependent on the volume itself, represented by a certain density of metals. To select an appropriate design for the aluminum brackets, the procedure was carried out utilizing the Analytic Network Process (ANP) technique. Through the conceptualizing approach, it has been demonstrated that the second design is superior to the alternative.