Scientific Journal "Metallurgy"

PROSPECTS FOR THE TRANSFORMATION OF UKRAINE’S FERROUS METALLURGY INTO “GREEN” METALLURGY

Yurii Vilkul — 2025-05-27

The presented work defines the physicochemical characteristics of a typical coke-free steel production scheme compared to the traditional process. The efficiency of the Swedish metallurgical industry has been proven, with its greatest achievement being the world's first production of "green" iron using the HYBRIT technology in June 2021.The paper outlines the key points from the speeches of participants at the International Forum "Green Metallurgy – Towards the Recovery and Transformation of Ukraine’s Industrial Sector," which took place on November 20, 2024, in Kryvyi Rih.It is emphasized that the determined technical concept of "green" metallurgy refers to a metal production process in which all technological components are carried out exclusively using renewable energy sources and without carbon dioxide emissions into the environment.This condition also applies to all materials used in metal production.Such metallurgy is only possible within the framework of a "green" economy, which remains a future endeavor, as the transition requires significant time and financial investment. Today, the focus is on taking the maximum possible steps toward clean "green" metallurgy.There are modern, efficient developments in specific steel production processes that almost fully comply with the principles of "green" technology. When selecting an industrial implementation method for "green" steel production, alongside environmental and techno- economic indicators, it is essential to consider the requirements for the characteristics of the raw materials.

METALLURGICAL AND TECHNOLOGICAL ASPECTS OF WELDING COMPOSITE AND DISSECTIOUS METALS

Anna Lapteva — 2025-05-27

When creating modern objects in aircraft engineering, rocketry, and space technology, there is a need to use not only individual components made of composites, which are often obtained by welding methods, but also to connect them with each other, as well as with homogeneous and heterogeneous materials, which is associated with certain difficulties.The main types of composite materials, their structure, properties and purpose are highlighted.The possibility of physical weldability of materials is considered: solubility in the liquid state, susceptibility to metallurgical processing of the weld pool metal.In this article the main problems connected with welding capacity оf composite materials with matrix from nonferrous metals and heterogeneous nonferrous metal aluminium + copper, alumi- nium + titanium, titanium + copper (oxide film, weld porosity, losses of strengthen fibres and particles, formation of intermetallic compositions, equivalent solid) and the ways that help to overcome them both on stage to preliminary prepare of wares before welding and during of the welding process are analyzed.It is shown that melting welding is the most technologically advanced type of composite material joining, but at the same time it is very complex due to delamination in the near- seam zone and porosity. Technological measures are presented, under which melting welding of composite materials will give satisfactory results. The permissible thickness of the intermetallic layer is indicated, at which the strength of the weld will be at a satisfactory level.The possibilities of pressure welding of dissimilar materials are considered.For all cases, the approximate strength of the resulting welded joints is given.The technical methods and technological recommendations by the welding this materials are given too.Modern tendencies on perfection welding capacity, technology and technique of manufacture from composite and heterogeneous nonferrous metals welded constructions are examined.

ANALYSIS OF INSTALLATION AND BASISING METHODS OF NODES OF TECHNOLOGICAL LINES OF METALLURGICAL SHOPPING PLANTS

Andrii Vlasov — 2025-05-27

Rolling production is the final stage of the metallurgical cycle, and the quality of finished products supplied to the consumer directly depends on the coordinated operation of all technological units. The high level of wear and tear of the main production assets of metallurgical enterprises necessitates not only their renewal, but also the constant modernization of outdated equipment. Since renewal is carried out in the conditions of existing production, this process involves complex installation work to integrate new or reconstructed equipment into already functioning production lines.Operation of mechanical equipment is a set of three interdependent processes: performance of technological operations, wear during operation and performance of repair actions to restore operability. The rate of wear of machines and mechanisms depends on both the intensity of technological actions and the quality of installation work, lubrication modes of friction units, periodicity and completeness of technical maintenance.The reliability of machines depends on the quality of design, technological and assembly work. Errors in dimensions, configuration, mutual arrangement of parts can lead to an unacceptable increase in forces and emergency failures. For metallurgical equipment, such errors often appear during assembly, which is understood as a set of operations to connect parts into a product. Thus, an important issue arises of establishing optimal methods for assembling metallurgical equipment in the conditions of a manufacturing enterprise in view of the possibility of minimizing all possible errors in assembly work.Known methods of assembly and verification of basic parts of technological equipment are somewhat outdated and require constant and continuous improvement. The most accurate and fast method of controlling the accuracy of assembly and installation of basic parts is optical-geodetic, which allows you to free up to 20% of working personnel and at the same time save up to 30% of working time compared to the string method of controlling the assembly of metallurgical equipment units.

MATHEMATICAL MODELING AND OPTIMIZATION OF TECHNICAL AND ECONOMIC INDICATORS OF PRODUCTION AND USE OF METALLISED MOLYBDENUM CONCENTRATE

Stanislav Hrigoriev — 2025-05-27

In the work, a study of technical and economic indicators of an active industrial experiment of smelting and using metallized molybdenum concentrate (spongy ferromolybdenum) was carried out. In domestic practice, the technology for the production of a new alloying material based on molybdenum in mine electric furnaces was developed and exploited for a long time and was optimized. A mathematical model of technical and economic indicators was developed, taking into account the largest number of technological factors. The result of mathematical modeling is a multifunctional indicator system. The limits of production indicators and expenditure coefficients of bulk materials were established and optimized, which made it possible to stabilize the quality of the target product.In the performed assessment of end-to-end economic efficiency when obtaining a new alloying material, there is a reduction in the cost of production technology and a reduction in expenditure ratios. In the assessment methodology, not only the general recommendations of the ratio were used, but also the original factors that were developed in actual work. In the efficiency assessment calculations, an improved technique was used with the specification of the relevant coefficients and prices for such materials as standard ferromolybdenum FMo52…FMo60, molybdenum concentrate of grades KMo1…KMo3, FMoG1…FMoG3 and steel P6M5.The new alloying material based on molybdenum FMoG differs from traditional ferroalloys smelted by ore or metalothermic methods by favorable technical and economic indicators: 7-8 times higher rate of assimilation of molybdenum by molten steel, reduction of oxidation potential during alloying – assimilation of chromium, molybdenum and vanadium increases by 4-10%.On the example of the production and use of spongy ferromolybdenum for steel alloying, an economic efficiency assessment was performed, which confirms the expediency and perspective of using alloying materials based on refractory elements in metallurgy.

MARKETING RESEARCH OF THE GLOBAL MAGNESIUM MARKET

Viktor Malyshev — 2025-05-27

Due to its unique physical, chemical, mechanical and biological properties, magnesium is widely used in many industries, in particular, in the automotive industry, aerospace and defense industry, construction, medicine and healthcare, food industry, electrical engineering and electronics. The industry of production and use of magnesium is constantly developing, is engaged in the search for new modern methods of obtaining magnesium and its compounds, which find new promising applications.The magnesium market covers the search for new sources of magnesium-containing raw materials, the development of new technologies for obtaining magnesium, research into the properties of new magnesium-containing materials and the possibilities of their use. In 2024, the volume of the global magnesium market was estimated at 5.62 billion USD and, according to forecasts, is expected to grow to 5.92 billion USD in 2025 and to 9.50 billion USD by 2026. by 2034 with a compound annual growth rate of 5.39% from 2025 to 2034.The global magnesium market was studied and factors of positive and negative impact on it were identified. According to the segmentation of the global magnesium market by type of production process, the leading position in 2022 was occupied by the thermal reduction of magnesium oxide with silicon with a share of 80%; by product composition in 2023 – the segment of metallic magnesium (39.2%); by geographical regions in 2024 – the segment of the Asia-Pacific region (35%); by application in 2024 – the segment of aluminum alloys (34%); by industry in 2022 – the segment of the automotive industry (38%). The main strategic trends and directions of further development of the global magnesium market are presented.

TECHNOLOGIES FOR THE SYNTHESIS OF HIGH-ENTROPY ALLOYS: CURRENT STATE AND FUTURE DIRECTIONS

Yurii Belokon — 2025-05-27

The article explores the conceptual foundations of high-entropy alloys (HEAs) and various technologies for their production. The analysis of traditional metallurgical methods, such as arc and induction melting, highlights their effectiveness in ensuring material homogeneity while emphasizing their limited capabilities in precise microstructure control. Powder metallurgy provides a uniform element distribution but is characterized by high energy consumption.Alternative methods, including laser melting and vapor phase deposition, offer new prospects for controlling alloy structures; however, their scalability is hindered by equipment costs and low productivity.Key technical challenges impeding the advancement of HEA production have been identified, including difficulties in microstructure control, uneven component distribution, and significant energy consumption. To address these challenges, a combination of traditional and modern methods is proposed, along with the use of numerical modeling to optimize production processes. Advanced alloy design approaches are based on the physicochemical analysis of components and take into account operational conditions.Modern methods for controlling the microstructure and mechanical properties of HEAs are reviewed. The application of laser melting, electro-pulse sintering, and vapor phase deposition technologies enables more precise regulation of material parameters and defect reduction.Additionally, the importance of developing new approaches to phase transformation control is emphasized, as this will facilitate the predictable formation of alloy structures.The prospects for scaling up HEA production are examined, highlighting the need for further research to enhance productivity and reduce costs. Strategic directions for integrating HEAs into industrial sectors, including aerospace, energy, and medicine, are proposed.A comprehensive approach to HEA production is suggested, incorporating prototyping, testing, and the adaptation of technological processes to meet industrial requirements. The potential of various production methods is assessed in terms of their economic efficiency and technical feasibility.Thus, this study enhances the understanding of HEA manufacturing processes, contributing to their broader application in high-tech industries.

CURRENT STATION OF SCIENTIFIC AND TECHNICAL PROBLEMS IN THE INFLECTION OF CHEMICAL ELEMENTS ON THE INDICATORS OF THE INDICATORS OF THE INTELLIGENCE OF LIVARY ALLOYS BASED ON NICKEL

Viktor Skachkov — 2025-05-27

A promising objective of modern scientific activity for young researchers** is the creation and production of competitive equipment, including gas turbine engines for aircraft and helicopters. Their development must be based on new-generation, energy-efficient, and resource-saving materials.Nickel–aluminum–chromium-based superalloys are critical materials for high-stress applications with highly efficient use in the aerospace sector, power generation, and transport industries. These alloys are distinguished by their ability to maintain creep resistance close to their melting temperatures and, overall, exhibit high strength.Single-crystal nickel superalloys are used in the aerospace industry as gas turbine blades, while wrought alloys are typically limited to turbine disks and auxiliary components. These alloys are specifically engineered to operate at high temperatures (above 600 °C), where most traditional materials lose their properties.Development of single-crystal heat-resistant nickel alloys with reduced density follows two primary approaches: optimizing chemical composition and reducing the content of heavy elements such as tungsten (W) and rhenium (Re), which allows for lower density without significantly compromising mechanical properties.The following alloys were analyzed (in wt.%): LDS-1101: Higher Co (9.85%) and Mo (7.1%) content enhances thermal strength; higher Re (2.95%) improves high-temperature creep resistance; significant Ta (6.25%) increases heat resistance but may raise density, LEK94: Higher Al (6.5%) and Ti (1.0%) promote γ'-phase formation (strengthening), but lack of Mo and high Ta content found in LDS-1101 are not fully compensated.Development of next-generation alloys involves numerous risks and challenges**, particularly in sourcing high-quality raw materials. This is one reason why substantial research into state-of-the-art nickel alloys is nearly impossible for individuals. Contributions to this field are typically made by large technological research companies in the defense or aerospace sectors, or by advanced research institutions.Typical 2nd-generation superalloys contain around 3 wt.% Re. In 3rd-generation alloys, this increases to approximately 6%. 4th-generation alloys include a small amount of Ru (5 wt.%).The concentrations of Ta, Co, Al, and W have remained relatively stable over time, while Mo and Ti are used in minor quantities. Cr content decreased through successive generations but increased again in the 6th-generation TMS-238 alloy and in low-Re superalloys.

ANALYSIS OF PHASE FORMATION PROCESSES IN COMPLEX ALLOYS

Viktor Skachkov — 2025-05-27

The study focuses on the phase formation processes in heat-resistant nickel alloys, which are critically important for the aviation and energy industries. These alloys operate under extreme conditions of high temperatures (up to 1373K) and mechanical stresses, particularly in turbine blades of aircraft engines, where exceptional strength and durability are required.In multicomponent systems, the interaction of numerous elements leads to the formation of solid solutions (γ-matrix), intermetallic compounds (γ'-phase), carbides (MC, M23C6), borides (M3B2), and oxide films. Thermodynamic principles, particularly Gibbs free energy minimization, determine the stability of these phases, while kinetic factors, such as atomic diffusion, influence their formation rate.The main phases in nickel alloys include: γ-matrix – a solid solution based on nickel with a face-centered cubic structure, ensuring plasticity; γ'-phase (Ni3(Al, Ta)) – an intermetallic compound occupying up to 70% of the alloy volume in materials like CMSX-4 and serving as the primary strengthening phase; сarbides, which enhance wear resistance; borides, which strengthen grain boundaries; oxide films, which protect against oxidation and reduce its rate by 30–40% at 1373K.Each alloying element plays a specific role: nickel forms the base; aluminum and tantalum contribute to γ'-phase formation; chromium, molybdenum, and tungsten promote carbide formation; boron strengthens grain boundaries; rhenium and ruthenium slow diffusion, increasing creep resistance; rare-earth elements (Ce, Y, La, Nd) form protective oxide films, improving heat resistance.Heat treatment optimizes the γ'-phase particle size (30–40 nm), increasing strength by 10–15%. Adjusting the alloy composition ensures phase balance, preventing harmful topologically close-packed phases, such as the σ-phase. Cooling rate control affects element segregation, and diffusion management, particularly using rhenium, which slows diffusion by 20–30%, enhances durability (Rhenium effect).

DETERMINATION OF ENERGY PARAMETERS OF THE WIRE DRAWING PROCESS THROUGH DOUBLE DRAWINGS

Kostyantyn Taratuta — 2025-05-27

This study focuses on determining the wire drawing tension when the wire is pulled through double dies arranged in series without any intermediate storage devices. Significant wear of the drawing dies (spindles) is observed in the production of small-section wire by cold drawing. This leads to deviations in the finished profile in terms of both shape and size.To address this issue, it is necessary to improve the drawing technology by implementing measures to reduce die wear. To achieve this, technical and technological production factors must be considered.The main ways to increase the service life of the drawing tool are: using new wear-resistant materials to produce dies; reducing friction in the deformation zone using new lubricants and ensuring a stable lubricant supply; using vibration drawing and drawing with counter tension; ensuring an effective cooling process for the dies; using equipment to prepare the wire for drawing; and improving the drawing process.The main objective of this study is to analyse the stress-strain state of the metal during wire drawing with counter-tension, created by additional (rough) drawing. These studies will facilitate the development of rational drawing routes, reduce drawing wear and increase process productivity.Traditional wire production methods usually do not involve the use of counter-tension in finishing operations. An exception is direct-flow drawing mills that operate with counter- tension. On these drawing mills, counter-tension is created by adjusting the speed of the drawing drums. However, using counter-tension on other types of drawing mill will significantly impact the technical and economic performance of production.The results of the study show that using counter-tension during wire drawing creates additional tensile stresses in the metal. Creating elastic and elastic-plastic deformations from counter-tension reduces compressive stresses in the friction zone.

COMPREHENSIVE SAFETY OF ELECTRICAL POWER TRANSFORMERS UNDER HOSTILE SHELLING: ELECTRICAL SAFETY, FIRE SAFETY, AND CIVIL PROTECTION

Volodymyr Gridiaiev — 2025-05-27

The article examines the comprehensive safety of power transformers under conditions of armed aggression and ongoing shelling of critical energy infrastructure. Emphasis is placed on the necessity of integrating three interrelated components: electrical safety, fire safety, and civil protection measures. Existing methods of physical protection for transformers are thoroughly analyzed. Particular attention is given to the impact of such protective structures on the thermal operating conditions of transformers.Based on three-dimensional thermal modeling of a TM-1000/10 transformer, accounting for heat exchange with the environment, it was found that without adequate ventilation, the temperature of the transformer oil can exceed 100 °C within just one hour of operation.This significantly increases the risk of thermal degradation of insulation, fire, or complete equipment failure.The study shows that ensuring sufficient air exchange is the key factor for the reliable operation of a transformer under protective enclosures. A model was developed to determine the relationship between the required air flow rate and the permissible temperature rise for the TM-1000/10 transformer.It was established that with a small allowable temperature rise (2–5 °C), the required air flow rate exceeds 10,000 m³/h, which may be challenging to implement in practice. In the range of 10–15 °C, the air flow rate decreases to 3,000–4,000 m³/h, which is typical for natural or forced ventilation systems.

NEUTRALIZATION OF HIGHLY MINERALIZED WASTEWATER FROM METALLURGICAL PRODUCTION USING AN INTERMEDIATE SOLID COOLANT

Gennadii Kozhemiakin — 2025-05-27

One of the main sources of environmental pollution at metallurgical plants is highly mineralized wastewater. The increase in the salt content in these waters is due to the use of soluble substances in metallurgical processes, chemical water treatment processes in closed equipment cooling systems, cleaning of waste pickling solutions and wash water in rolling shops. In addition, mineral impurities enter the wastewater when liquids come into contact with solid or dissolved salt-containing materials. One of the key tasks of environmental protection in metallurgy is the effective purification of such wastewater from dissolved minerals.The most common technologies for removing salts from wastewater are reverse osmosis, electrodialysis, ion exchange and thermal desalination. However, in most cases, concentrated brines are formed as a result of such processes. A more rational option is to isolate salts in solid form, which significantly facilitates their further transportation, disposal or burial. Given this, thermal methods of wastewater treatment are considered promising. Evaporation of mineralized wastewater at metallurgical plants leads to accumulation of high concentrations of salts in them. In addition to traditional carbonate and sulfate scale, silicate, ferrous and other deposits can also form on heat exchange surfaces. To avoid these problems, it is advisable to use solid materials as an intermediate heat carrier. Such installations usually use metal balls heated by hot gases, on the surface of which salts crystallize, which are then removed. The heat engineering features of the evaporation process using a solid heat carrier are analyzed and the dependences of the heat transfer coefficient on the main process parameters are established. Based on experimental studies, a method for neutralizing highly mineralized wastewater is proposed, which allows for the effective use of low-potential secondary energy resources.

EFFECT OF FEED MIX PROPERTIES AND SURFACTANT APPLICATION ON ENERGY CONSUMPTION AND PRODUCTIVITY OF AN INDURATION MACHINE: INDUSTRIAL ASSESSMENT AND PREDICTIVE MODELLING

Volodymyr Kukhar — 2025-05-27

The article investigates the energy consumption of an induration machine, which performs the full cycle of thermal treatment of iron ore pellets – from drying and preheating to induration, heat recovery, and cooling. Particular attention is given to the influence of the physicochemical properties of the feed mix, specifically its moisture content, particle size distribution, and the use of surfactants (surface-active agents), on the overall specific consumption of electric power and natural gas, as well as on the unit’s productivity. Industrial- scale trials were conducted at one of the leading iron ore beneficiation plants in the Kryvbas region in connection with a transition from a baseline (in-house) concentrate to raw material produced by another regional plant, which had been pre-treated with a nonionic surfactant.It was found that the increased fineness and hydrophilicity of the new concentrate required additional moisture to be added to the feed mix, which significantly affected the thermal regime of the machine and overall energy consumption. Based on the collected experimental data, regression models were developed to quantitatively predict the specific consumption of electricity and gas as functions of technological parameters. The results demonstrate that the key influencing factors are the moisture content of the feed mix and the daily productivity of the induration unit. An increase of 17.73% in specific electricity consumption and 33.25% in specific natural gas consumption was recorded, accompanied by a 9.55% reduction in throughput. These findings are relevant for professionals in the fields of energy management, power engineering, and thermal analysis in metallurgy, particularly when designing strategies to optimize energy consumption under industrial operating conditions.

ENERGY SAVING STRATEGY AT INDUSTRIAL ENTERPRISES

Serhiy Bashliy — 2025-05-27

The implementation of an energy saving strategy at industrial enterprises is a key component of energy efficiency management, taking into account the specific operational characteristics of the enterprise's energy systems.This work provides a detailed analysis of the processes involved in developing and implementing such strategies aimed at the long-term rational use of energy resources.An analysis of expenditures in the production, distribution, and consumption of electricity reveals that the majority of losses (up to 90%) occur at the consumption stage, while transmission losses account for only 9–10%. This underscores the necessity of focusing primary efforts on improving the efficiency of end-use energy consumption.A primary direction in this context should be the development and comprehensive implementation of organizational, technological, and techno-economic measures, unified into a single energy saving strategy.Special attention is devoted to identifying key energy saving measures based on the adoption of advanced energy consumption technologies that influence the formation of the chosen strategy.The stages of strategy implementation are outlined, including the development of a performance indicator system and an algorithm for assessing the effectiveness of implemented measures. It is demonstrated that the fundamental principle in justifying energy saving initiatives is the optimization of implementation costs.An effective energy saving regime is particularly important for equipment with variable load levels, such as conveyors, pumps, and fans. Capacitor units and frequency-controlled drives are widely used to reduce energy losses.A balance-based approach is proposed to optimize energy saving processes. A mechanism for constructing this balance is defined, based on iterative coordination of energy inflows and consumption within the enterprise. This approach takes into account internal technological needs, production plan execution, and potential production expansion–while simultaneously ensuring energy supply stability.

RESEARCH ON THE INFLUENCE OF THE SCRAP PORTION ON THE OPTIMAL PARAMETERS OF THE OXYGEN-CONVERTER MELTING

Olеksandr Kharchenko — 2025-05-27

The study investigates the influence of the proportion of scrap and other charge materials on the optimal parameters of oxygen-converter smelting based on a thermodynamic analysis of the “metal-slag-gas” system using the Gibbs chemical potential method. Utilizing the “Excalibur” software suite, experimental-computational modeling and systematic analysis were performed on a set of interrelated parameters of oxygen-converter smelting. These include pressure (including ferostatic metal pressure), pig iron temperature, temperature and chemical composition of the steelmaking bath in the converter, slag regime, initial mass of steel and pig iron scrap, refractory lining erosion, material preheating, oxygen mass for smelting, flux material mass, and a range of other technological and geometrical parameters of the oxygen converter.Using the simplex method of linear programming, parameter optimization of the oxygen- converter smelting process was conducted for several scenarios. Graphical dependencies were developed showing the impact of material mass fractions–especially scrap–on the content of chemical elements in the final semi-product and slag. The technology of oxygen- converter smelting with increased scrap content and reduced molten pig iron in the charge materials was analyzed. The influence of the physical and chemical properties of charge materials on the thermal performance of converters was determined, along with the feasibility of partially replacing pig iron with scrap to save resources and enhance the technical and economic efficiency of smelting.This modified technology, featuring a higher share of scrap and lower share of molten pig iron, is recommended for producing low-carbon steel grades. It is concluded that achieving high-quality steel from converter semi-products requires post-furnace treatment with thorough deoxidation and desulfurization. Additional conclusions were drawn regarding the practical application of the study’s findings.

METHODOLOGICAL APPROACHES TO THE SELECTION OF SYSTEMS RELIABILITY-CENTERED MAINTENANCE METALLURGICAL EQUIPMENT

Kostiantyn Taratuta — 2025-05-27

Modern metallurgical production is a high-tech, material-intensive industry. The uninterrupted operation and productivity of this process depend largely on the condition and functionality of the technological equipment used. The efficiency of the production process depends on the reliable operation of the equipment. Various maintenance systems are used to ensure the equipment operates reliably and efficiently. This work focuses on the features of choosing a maintenance system that prioritises reliability in metallurgical production conditions.The main objective is to develop procedures that facilitate the selection of maintenance and repair strategies.The article considers the pros and cons of different maintenance systems. The key characteristics of these systems are identified.Within the framework of the recommended reliability-focused maintenance system, attention is given to choosing a repair strategy. To this end, the work classifies metallurgical equipment failures into three levels. The first level is based on the nature of the failure, the second level is based on the factors involved, and the third level is based on the consequences and the possibility of elimination. Classifying equipment involves determining the criticality level of failures. Taking into account the level of 'criticality' for each type of equipment, the most effective strategy should be determined.Decision-making diagrams are useful for selecting a maintenance strategy. These diagrams provide a visual representation of the logic involved in choosing between alternative strategies based on specific conditions. The decision-making diagram presented in the article helps to structure the process of selecting a maintenance and repair strategy by reflecting possible actions and conditions, as well as their consequences, in the form of sequential steps.Thus, the choice of a maintenance and repair strategy for metallurgical equipment directly affects the safety, continuity of production and technical and economic indicators of the enterprise.

ENGINEERING IN PROVIDING TERRITORIES OF THE WORLD EFFECTIVENESS OF THE FUNCTIONING OF HYDROPOWER

Serhiy Bashliy — 2025-05-27

A comparative analysis of the efficiency of hydropower operation in leading countries around the world has been conducted. The best results are demonstrated by countries where hydropower serves as a primary source of energy supply. An important factor in improving efficiency is the presence of pumped storage capacities. Ukraine belongs to the group of countries that use hydropower to maintain the energy system balance.In today’s conditions, the development of renewable energy, including hydropower, largely focuses on aggregate indicators of installed capacity, the volume of newly commissioned capacity per year, and, occasionally, the amount of electricity generated. However, the issue of hydropower efficiency often remains overlooked. Since 2002, the All-Ukrainian Public Organization "Association Ukrhydroenergo" has been active in Ukraine. The article aims to conduct a comparative analysis of the efficiency of hydropower performance in leading countries. The main objectives are to identify key factors influencing hydropower efficiency, analyze the experience of leading countries, and explore the possibility of applying this experience to the development of Ukraine's hydropower sector.The research is based on a comparative analysis method, evaluating operational efficiency by the ratio of electricity generated to installed capacity. The methodological foundation includes the analysis of the natural potential of territories (considering relief and river networks), statistical research, methods of logical generalization, and comparative analysis.It has been established that the efficiency indicators of Ukrainian hydropower are comparable to those of major European countries.

ОТРИМАННЯ ТИТАН-МОЛІБДЕНОВИХ СФЕРИЧНИХ ПОРОШКІВ МЕТОДОМ PREP З ВИКОРИСТАННЯМ КАТОДІВ, ВИГОТОВЛЕНИХ БЕЗКАМЕРНОЮ ЕЛЕКТРОШЛАКОВОЮ ВИПЛАВКОЮ

Oleksii Kapustian — 2025-05-27

The rapid development of 3D-printing technologies justifies the relevance of the production of powders by the PREP method. Confirmation of this is active participation in scientific research of innovative materials, development of technologies, equipment of professional institutions of Ukraine, Europe, China and America. Titanium and titanium alloy powders are in wide demand as heat-resistant, heat-resistant and corrosion-resistant materials. It is known that doping titanium with molybdenum from 3 % to 10 % increases its corrosion duration in solutions of inorganic acids from 20 to 300 times, which makes this two-component alloy a promising material for obtaining highly corrosion-resistant powders. The work provides evidence of the high biocompatibility of two-component titanium-molybdenum alloys. For the production of a wide range of medical parts, it is most advisable to use layer-by-layer synthesis with two-component powder. Titanium-molybdenum cathodes were made from ingots with a diameter of 55 mm, which were obtained using the technology of chamberless electroslag smelting. The consumable electrodes were made of titanium and molybdenum strips, which were connected into a package using the TiG method. The titanium-molybdenum ingot had a smooth surface, a dense defect-free macrostructure; no inclusions of unmelted molybdenum particles were detected. It was established that the hardness of the casting and the content of molybdenum and titanium in the cross section almost did not change. Center – 33.0…33.2 HRC, Ti – 91.15 %, Mo – 8.83 %; half of the radius – 33.0…33.5 HRC, Ti – 91.6 %, Mo – 8.84 %; edge – 33.5…34.0 HRC, Ti – 91.10 %, Mo – 8.90%. The sprayed powder had the following chemical composition: Ti – base, 8.700% Mo; 0.180% Fe; 0.050% C; 0.030% Si; 0.035% N; 0.150% O; 0.009% H, particle shape – spherical, bulk density 1.9…2.2 g/cm3 and fractional composition: 40…50 μm – 7%; 50…60 μm – 15%; 60…70 μm – 23%; 70…80 μm – 28%; 80…90 μm – 17%; 90…100 μm – 7%. In general, the powder meets the quality criteria of additive powders.

TITANIUM HYDRIDE AS ONE OF THE MAIN PRODUCTS IN THE PRODUCTION OF TITANIUM POWDERS

Olena Akhinko — 2025-05-27

Titanium and titanium powders are attractive for a wide range of structural and functional applications due to their excellent specific strength, toughness, stiffness, and corrosion resistance. When exposed to hydrogen, titanium forms hydrides in the form of TiHx, leading to cracking and mechanical failure as a result of lattice distortion and stress accumulation. The kinetics of the hydriding process depends on several factors, including the critical threshold of hydrogen saturation within Ti, the nature of hydrogen’s interaction with the protective surface oxide, mass transfer rate, and the kinetics of nucleation and phase transformations.The high production cost associated with existing manufacturing technologies prevents widespread use of titanium in civilian industries such as automotive manufacturing, consumer goods production, and others. Particularly with the active development of additive manufacturing, an urgent task is to develop methods for obtaining metal powders with low production costs that still meet high consumer requirements.An alternative to reducing production costs for obtaining metallic titanium lies in the methods inherent to powder metallurgy. The technological properties of titanium powders– such as their suitability for shaping and sintering by powder metallurgy methods–enable their use across various industries, including machine tool building, construction, aerospace engine manufacturing, and precision instrumentation.Ion implantation is often used to modify the chemical, mechanical, or electrical properties of materials. This method was applied for implanting H ions into a Ti matrix to study hydride behavior.The main problem of ion implantation is radiation damage transferred to the matrix due to the need to accelerate the implanted ions for penetration. During this process, accelerated ions transfer their kinetic energy and momentum to the electrons and nuclei of the target atoms, generating a significant number of defects, such as atomic vacancies or interstitial ions. In ion implantation, the primary defects are located near the material’s surface and are retained in these defect sites.