In the process of manufacturing iron-aluminum alloys, the prospects of reducing the costs spent for the refractory and charge materials, as well as for the supply of thermal and electric energy are connected with the realization of the exothermal process of melting of the thermite charge, i.e., in fact, industrial wastes in the form of scale and metal shavings, in the reactor without applying traditional melting units. In view of the high temperature of formed melts, it seems reasonable to use carbon materials as refractories. The durability of the reactor strongly depends on the number of thermal cycles and the possibility of ensuring the mechanical strength and functionality of its elements subjected to the most aggressive thermal effects of the melts. As a result of a series of experiments, we determine the possibility of weakening of the thermal effect of iron–aluminum melts formed as a result of the exothermal reaction on the material of the graphite reactor by regulating the content of active aluminum. Moreover, we propose a version of measures connected with the possibility of updating the design of the graphite reactor aimed at increasing its service life.

Для процессов получения железоалюминиевых сплавов перспектива снижения затрат на огнеупорные и шихтовые материалы, тепловую и электрическую энергию видится в реализации экзотермического процесса плавления термитной шихты, представляющей собой промышленные отходы в виде окалины и стружки металлов, в реакторе без применения традиционных плавильных агрегатов. Ввиду высокой температуры образующегося расплава обосновано использование углеродных материалов в качестве огнеупоров. Стойкость реактора во многом зависит от количества теплосмен, обеспечения механической прочности и функционала его элементов, подвергающихся наиболее агрессивному теплофизическому воздействию расплава. В результате серии экспериментов определена возможность снижения теплофизического воздействия железоалюминиевого расплава, образующегося в результате экзотермической реакции на материал графитового реактора регулированием содержания активного алюминия; представлен вариант мероприятий, связанных с модернизацией конструкции графитового реактора, направленных на увеличение срока его эксплуатации. For the processes of producing iron-aluminum alloys, the prospect of reducing costs for refractory and charge materials, thermal and electrical energy is seen in the implementation of the exothermic process of melting the thermite charge, which is industrial waste in the form of scale and metal shavings, in a reactor without the use of traditional melting units. Due to the high temperature of the resulting melt, it seems justified to use carbon materials as refractories. The durability of the reactor largely depends on the number of thermal cycles, ensuring mechanical strength and functionality of its elements that are exposed to the most aggressive thermophysical effects of the melt. As a result of a series of experiments, the possibility of reducing the thermophysical effect of an iron-aluminum melt formed as a result of an exothermic reaction on the material of a graphite reactor by regulating the content of active aluminum was determined; a variant of measures related to modernizing the design of a graphite reactor aimed at increasing its service life is presented.

Aerospace, manufacturing, and shipbuilding industries strive to enhance their competitiveness by optimizing material utilization and improving production processes. The investment casting process offers the capability to fabricate intricate and precise components using a diverse range of alloys. However, this method is not without its drawbacks, including high manufacturing costs and a significant rate of defective castings, which can reach up to 30 %. These defects primarily arise from the stresses imposed on the wax patterns and ceramic molds, leading to their distortion. To address this issue, efforts have been made to reduce stress by employing compacted wax powders for the production of investment patterns. However, stress relaxation in the wax patterns remains a concern as it can result in elastic deformation of the compacted material and subsequent alterations in the final product dimensions. To mitigate this issue, a series of tests were conducted with the objective of studying stress relaxation under constant compression strain, as described by the Kohlrausch equation. The obtained results provide valuable insights that enable the prediction of the ultimate dimensions of patterns created using different grades of wax.

Searching for alternatives to diversification of production facilities that do not require significant material and energy costs is relevant in the face of pressing external factors. One of the promising technological fields of alloy production in metallurgy is the application of aluminothermic processes of remelting of thermite charge consisting of secondary materials (scale, chips of ferrous and nonferrous metals), used to produce a wide range of metal products without significant costs associated with the reequipment of production units. The possibility of controlling the parameters of alloys and properties of the final metal product formed by aluminothermic processes is implemented primarily by reducing the temperature of the metal phase of the melt by introducing inert fillers into the composition of mixtures, as well as holding the melt in the crucible before casting. The chemical composition, structure, and physical and mechanical properties of iron-carbon alloys are significant in forming several operational characteristics. The paper presents experiments aimed at studying the effect of the initial components of thermite charge materials used to produce iron-carbon alloys in aluminothermic processes, as well as the melt holding time in a crucible before casting on the chemical composition, microstructure, hardness, strength indicators, and the fracture characteristics. The focus of experimental investigations is on industrial applications in the metallurgical and machine-building sectors.

The growth in metal intensity of industrial production and the volume of consumption of finished metal products determine the relevance of development and research of energy efficient technological processes aimed at reducing costs by reducing the number of operations while maintaining product performance. In mechanical engineering, the problem of obtaining blanks with increased dimensional and geometric accuracy and complex configuration is solved by using a common method of investment casting. Expansion of the use of such technological approach to produce blanks in mechanical engineering is hindered by a number of physical phenomena associated with the thermal expansion of investment and ceramic materials, which leads to an increase in the product final cost. A significant number of defect-forming factors can be eliminated by applying an innovative solution consisting in the formation of porous removable models by compacting mixtures based on waxy materials. This solves the problem of material shrinkage and increases the crack resistance of ceramic molds, which significantly reduces the share of machining in the overall volume of technological operations. Technical tests of the new method have revealed the reason why the machining of castings cannot be completely eliminated at present. The problem mainly lies in elastic response of compacted material of the model mixture, which, in some cases, affects the increase in the compacts size. This paper considers the effect of initial packing of spherical-shaped elements simulating one- and two-component model mixtures on the stress-strain state of a powder body subjected to unilateral compaction in a rigid cylindrical matrix to technologically justified density values. The results of the experiment are presented in the form of stress-strain relations. Preferable conditions of compact formation with minimal values of elastic response of the compacted material are considered.

In order to achieve enhanced dimensional and geometric accuracy in castings from a broad range of alloys, special processes are typically used, whose improvement, in some cases, aims to eliminate the need for machining operations on the blanks. One such process is experimental investment casting using consumable porous patterns obtained by pressing wax-like powders of model compositions. When forming the surface of such porous patterns, the geometric parameters of the mold cavity of the press die, whose design ensures the directed transfer of load from the pressing elements to the entire volume of the compacted material, are of paramount importance. During the development of the method for obtaining experimental patterns, it was possible to eliminate defects arising due to thermophysical phenomena in materials (mainly due to their internal porosity): shrinkage of the pattern material, formation of cracks within the ceramic mold, and its failure. The observed phenomena that lead to defects occur at various stages of the technological process, including the production of investment patterns and ceramic shell molds, the melting of ceramic model materials, and the casting of the melt into the molds. In addition to the definite advantages of this approach to forming compact structures, a disadvantage should be mentioned: the variation of their geometry due to the elastic return of the compacted material resulting from overconsolidation or uneven loading of compact sections of varying thicknesses. It is possible to achieve controlled loading of a powder body by compacting it under centrifugal forces to obtain compacts of complex configurations, including bodies of revolution. This paper examines the influence of various process parameters, which accompany the action of the centrifugal field, on the characteristics of compacted powder bodies made from wax-like materials used to create pressed investment patterns with improved dimensional and geometric accuracy. The study compares the calculated rotation speed of the press dies, ensuring the compaction of the powder body to a technologically acceptable density while considering its desired geometry, with the experimental results. The paper also identifies scenarios to enhance the energy efficiency of powder body compaction from wax-like composite materials under centrifugal forces.

The decrease in integration processes in metallurgy and mechanical engineering is related to the current geopolitical aspects of global market conditions and uneven production, distribution, and consumption of final metal products. Consequently, it evokes a need for searching for energy- and material-efficient technological methods that ensure stable load and development of enterprises. One of these technological directions includes the development of possibilities for producing a layered composite comprising metals and alloys with considerable variations in their several properties. While creating bimetallic con- glomerates, the goal of obtaining a composite metal product with a set of unique characteristics, such as a combination of the high mechanical strength of the alloy forming the base and abrasive wear resistance, corrosion resistance, electrical and thermal conductivity of the coating metal, are achieved. In some cases, the heterogeneity of contacting alloys in chemical and phase composition leads to electrochemical corrosion of unprotected areas and low strength of the contact zone of dissimilar materials, which prevents the broad expansion of technologies for forming bimetallic products. This research presents the origins of the aforementioned flaws in bimetallic compounds and provides promising methods for obtaining metal composites and improving their characteristics.

A growing demand for structural materials with a set of unique characteristics, enabling the use of products under increased mechanical loads, elevated temperatures or chemically aggressive environments, is becoming a global trend in the industry, and especially in the field of metal-intensive manufacturing. These materials include intermetallic compounds based on metal aluminides. Materials of this nature are widely used as coatings to increase the service life of the products, reduce their weight and consumption of alloying materials. However, low ductility of such materials determines their low demand for products designed for use under the impact or alternating loads. The paper analyzes advantages and dis-advantages of intermetallic materials containing aluminum, modern methods of their use, and prospects for extending their applicability for the production of new metal products.

Рост промышленного производства стимулирует развитие заготовительных производств. С целью снижения материалоемкости производства, повышения экономической эффективности, снижения экологической нагрузки, повышения надежности и долговечности машин совершенствуются технологические процессы получения и обработки материалов и изделий. Задачи, стоящие перед современным машиностроением, обусловливают наличие повышенных требований к материалам и компонентам машин и механизмов. Ведется поиск новых способов обработки известных доступных материалов для улучшения комплекса их свойств с целью использования их в новых для них областях, в том числе в условиях сложного нагружения и агрессивного внешнего воздействия. В работе рассматривается новый способ интенсивного пластического деформирования металлических заготовок в виде полусферического слоя, выполненных из высокочистого алюминия. Упрочнение материалов интенсивным пластическим деформированием – это широко используемый способ улучшения механических характеристик материалов и изделий, в том числе не упрочняемых термической обработкой. Тем не менее, возможность этого метода совершенствования ограничена прочностью обрабатываемых материалов. В статье представлены результаты экспериментальных и теоретических исследований процесса упрочнения полусферических заготовок, в том числе приведена математическая модель процесса, основанная на деформационной теории пластичности. The growth of industrial production stimulates the development of procurement industries. In order to reduce the material consumption of production, increase economic efficiency, reduce the environmental burden, increase the reliability and durability of machines, technological processes for the production and processing of materials and products are being improved. The tasks facing modern mechanical engineering determine the presence of increased requirements for materials and components of machines and mechanisms. A search is underway for new methods of processing known available materials to improve the complex of their properties in order to use them in new areas for them, including under conditions of complex loading and aggressive external influence. The paper considers a new method of intensive plastic deformation of metal blanks in the form of a hemispherical layer made of high-purity aluminum. Hardening of materials by severe plastic deformation is a widely used method for improving the mechanical characteristics of materials and products, including those not hardened by heat treatment. However, the possibility of this method of improvement is limited by the strength of the processed materials. The article presents the results of experimental and theoretical studies of the hardening process of hemispherical workpieces, including a mathematical model of the process based on the deformation theory of plasticity.

Increased industrial production stimulates the development of procurement industries. Technological processes for the production and processing of materials and products are being improved to reduce the material consumption for production, increase economic efficiency, reduce the environmental burden, and increase reliability and durability of machines. The tasks in modern mechanical engineering determine the material and component requirements of machines and mechanisms. New methods for processing known available materials to improve the complex of their properties to use them in new areas, including under conditions of complex loading and undesirable external influence. Our paper discusses a new method for the intensive plastic deformation of metal billets in the form of a hemispherical layer made of high-purity aluminum. Hardening of materials by severe plastic deformation is a widely used method for improving the mechanical characteristics of materials and products, including those not hardened by thermal processing. However, the possibility of this improvement method is limited by the strength of the materials processed. This article presents the results of experimental and theoretical studies on the hardening process of hemispherical billets, including a mathematical model of the process based on the deformation theory of plasticity.

Under industrial conditions, melt for the production of cast products from wear-resistant steels is produced mainly by modifying iron-carbon-based alloys with ferrotungsten. Ferrotungsten production is a material-intensive and energy-consuming process that does not allow the direct use of ore concentrates as a modifier due to their complex chemical composition. The growth of the global consumption of wear-resistant steels and products from them necessitates search for and development of alternative methods to produce such alloys. The aluminothermic remelting of mixtures consisting of scale, reducing agent, and tungsten-containing component is aimed at solving the problems of processing man-made formations to produce metal products in the form of wear-resistant steel castings. Scheelite concentrate is used in the experimental process, which makes it possible to reduce the processing chain of tungsten use to one stage. The results of studies of the aluminothermal process of producing castings from thermite compositions are presented. The pattern of influence of the content of reducing agent and scheelite concentrate on the physical and mechanical properties of the metal is experimentally established.

The practice of manufacturing tungsten-containing wear-resistant steels and products made from them currently comes down to alloying iron-carbon alloys with ferrotungsten. Preparation of ferroalloys from ore concentrates is a multiple operation, energy- and material-intensive process. It is proposed to reduce production costs related to separate manufacture of ferrotungsten and iron-carbon alloys by combining the specified stages into one using metallothermy. Tungsten-containing iron-carbon alloy formation is accomplished by an exothermic reaction in specially formulated mixtures containing a reducing agent, iron oxides, and scheelite concentrate. Use of available and cheap local crude ore of complex chemical composition and metallurgical scale may give rise to an unpredictable nature of chemical reaction and also uncertainty of the final product chemical composition. In order to establish features of the effect of reducing agent and scheelite concentrate within thermite compositions on metal final yield and chemical composition of alloys prepared by metallothermy research is conducted connected with aluminothermic preparation of iron-carbon alloys containing tungsten.

Показаны современные способы ведения безвзрывной (механической) добычи твердых полезных ископаемых и основные виды бурового вооружения для ведения механической добычи и выемки горной породы. Рассмотрены перспективы улучшения буровых установок и карьерных комбайнов, а также упомянута возможность применения автоматизированной техники при добыче полезных ископаемых. Анализом методов повышения энерго- и ресурсоэффективности бурового вооружения выявлена проблема малой эффективности и высокой стоимости различных процессов армирования. Определен и проанализирован перспективный метод армирования бурового вооружения.

Obtaining the desired characteristics of products having complex geometry from compositions comprising powdered dissimilar materials used in the formation of consumable patterns allows the scope of application of specific precision casting methods to be extended. It is established that, when forming compacts having complex configurations using a mixture of wax and water-soluble components, it is impossible to achieve the distribution of properties in the volume of the final product, which determines the change in the geometry of compacts as a result of the elastic response of compacted material. The issue associated with the elastic response of such compacted material can be solved in an experiment, establishing the influence of the initial packing and compacting parameters of wax elements on the stress-strain state of the compact. In the paper, the research results represented as experimental polynomial dependences of stress on deformation in compacted bodies with various initial packing options, deformable plastic and elastic elements, are presented. The means of controlling the dimensional and geometric parameters of the final compacts from wax model materials obtained in the process of uniaxial compaction by regulating its stress-strain state are presented.

Changes in the unique properties of cast metal, including density, crystalline structure, and mechanical strength, can be formed in the direction from the rotational center of a mold to its periphery by applying centrifugal forces on a crystallizing melt. The versatile method can be applied to a wide range of alloys for obtaining castings weighing from several grams to tens of tons. However, significant energy and material consumption determines the efficiency of its application under conditions of predominantly mass and large-batch types of production. While the centrifugal method is currently used to produce castings of rotational parts, such as pipes, rings, and various cylindrical products, the thermophysical action of a centrifugal force field on alloys is of interest not only for the production of cast billets, but also for the directed structural formation of various nature materials, including composite ones. In order to expand the range of applicability of the centrifugal process in industrial settings, this paper presents the results of an analysis of current practices for producing alloys and manufacturing cast billets. Additionally, its advantages in comparison with fixed mold casting methods and options for eliminating its disadvantages are specified along with an identification of current trends in energy and resource efficient methods for the structural formation of materials, including those obtained from secondary raw materials. The effect of centrifugal action on crystallizing melts obtained by aluminothermic remelting of thermite compositions is shown.

The article discusses the types of various dusty iron‑containing waste generated in metallurgical and foundry production. Rational waste processing technologies are considered. The analysis of the chemical composition of iron‑containing waste, morphology and particle size is presented. Variants of processing and use technology that are acceptable for the conditions of the Republic of Belarus are proposed.

The influence of the fraction of the powdered waxy material to be compacted and the holding time under load on the residual stresses and the elastic response of the compacts is studied. The elastic response is experimentally found to be minimal in the compacts with a porosity of 7–12% at residual stresses less than 0.02 MPa in the compacted material.

The paper considers the possibility of reducing the use of crude ore for metal product by using aluminothermy, which facilitates effective integrated processing of metal waste generated by engineering and metallurgy facilities in the form of mill scale, ferrous and non-ferrous metal swarf with simultaneous castings production. The paper studies the impact patterns of thermite components ratios on the parameters of extracting chemical elements from the source components, metal phase output and its chemical composition. The possible applications for experimental alloys resulting from controlled exothermic reactions are determined for supplying castings and melting stock to blank production for mechanical engineering facilities.