This work presents a study of fine grinding processes in a novel vibration mill design that implements a combined particle loading principle: horizontal bilateral and vertical unilateral impact. It is shown that traditional grinding methods face limitations caused by size hardening, low energy efficiency, and particle agglomeration, which hinder achieving the required fineness. To improve grinding performance, a combination of vibrations in two mutually perpendicular directions is proposed, forming a complex stress–strain state within the particles. A model describing the motion of the grinding media was developed based on determining the horizontal, vertical, and resultant velocities. Calculations were performed for three operating modes of the mill: separate action of horizontal and vertical vibrations, as well as their combined application. It was established that the combined mode increases the resultant velocity to 1.40 m/s and the specific interaction energy of the grinding media to 0.9869 J/kg, which is 25% higher compared to using only horizontal vibrations. The results confirm that simultaneous action in two directions enhances energy efficiency, improves grinding fineness, and reduces the tendency of particles to agglomerate. The proposed vibration mill design and theoretical model may be applied in the development of energy-efficient technologies for fine and ultra-fine grinding of materials of various origins.

https://doi.org/10.48081/NiTK3.2026/7-17

2026

Issue 3

The authors analyzed the possibility of involving in the processing of iron–containing waste generated during the production of alumina from bauxite in Kazakhstan using alternative carbon (C and CO) reducing agents - hydrogen (H2) and methane (CH4). In this article, a thermodynamic analysis of the process of reducing minerals that are part of ferrous sands and dump sludge with reducing agents – C, CO, H2, CH4. Outotec Technologies' HSC Chemistry 9.0 software was used for calculations. In the calculations, the studied temperature range was assumed to be within 100-1500 0C, the pressure within 101.33 kPa. Thermodynamic analysis in the studied temperature and pressure range clearly indicates the possibility of using hydrogen-based reducing agents alternative to carbon to recover iron from alumina production waste in Kazakhstan, which will contribute to achieving the UN Sustainable Development Goals and carbon neutrality in metallurgy. The research was carried out within the framework of grant funding from the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan for a competition for grant funding for scientific and (or) scientific and technical projects for 2024-2026 under the project AR23487674 "Integrated processing of bauxite in Kazakhstan with additional iron recovery by alternative reducing agents in the implementation of the low-carbon development strategy".

https://doi.org/10.48081/NiTK3.2026/315-330

2026

Issue 3

Loss of tightness of the sealing surfaces of pipe fittings is one of the most common causes of pipeline failures. The most loaded valve assembly is the wedge gate, which operates under harsh conditions of tribological wedge–saddle contact with significant pressure drops and intense flow dynamics. When the wedge is planted and moving, local stresses on the sealing chamfers can exceed the yield strength of the material, causing adhesive setting, scuffing, and intense plastic shear of the surface layer. The additional effect of hydrodynamic factors of the working environment – cavitation and waterjet erosion – significantly accelerates the destruction of the microstructure of structural steels and surfacing materials. Timely prevention of node failure requires a comprehensive analysis of the processes in the contact area, combining numerical modeling with metallographic studies. Joint numerical modeling makes it possible to determine with high accuracy the location of the zones of maximum equivalent stresses according to Mises, taking into account the physical and mechanical properties of the working medium. A comparison of the calculated stress concentration zones with metallography data and microhardness profiles reveals the physical nature of corrosion-mechanical and erosive wear. Thus, pitting corrosion and cavitation destruction prevail in the aquatic environment; high-speed gas flows provoke intense erosive wear; and viscous petroleum products change the distribution of the lubricating layer and contact pressure. The formation of wear-resistant surface layers through corrosion-resistant surfacing and surface plastic deformation reduces the destruction of the microstructure and prevents the nucleation of microcracks. A reasonable choice of the geometry of the contact pair and the technological parameters of hardening ensures that the required sealing class of the gate according to GOST 9544-2015 is maintained throughout the entire standard service life of the valve.

https://doi.org/10.48081/NiTK3.2026/101-118

2026

Issue 3

The article addresses the reduction in the service life of steel-cord conveyor belts caused by displacement of the steel cords from their nominal positions. It is shown that even minor deviations in cord geometry lead to a non-uniform distribution of tensile forces, stress concentrations, the development of adhesive failure, and the accelerated accumulation of fatigue damage. To address this problem, a method for equalizing the maximum strains in the belt’s transverse sections is proposed, based on optimizing the material-laod cross-section into characteristic regions, determining the loads using Zhuravsky’s theorem, and calculating deflections based on flexible-string theory. As a result of the optimization, the belt operates as a beam of uniform strength in bending, ensuring a more uniform distribution of strain and wear. Calculations demonstrated that the number of cords could be reduced by 20-40% without decreasing the load-bearing capacity of the belt carcass, while also reducing the belt’s weight and cost and extending its service life by an average of 20%. The results confirm that improving the carcass design is an effective means of enhancing the geometric stability f the steel cords and extending the service life os steel-cord conveyor belts.

https://doi.org/10.48081/NiTK3.2026/535-544

2026

Issue 3

The main problems of producing castings by the Lost Foam Casting (LFC) method are as follows: – carburization of the surface layer of steel castings during the burnout of the polystyrene model; – the high cost of foundry polystyrene used as a model material. This significantly increases the cost of the final products and limits the widespread application of the LFC method in manufacturing. In global practice, construction polystyrene granules are not used for producing models in LFC. However, previous studies have demonstrated the possibility of using them as a component of the model material. In addition, controlling the structure, and therefore the properties, of the resulting castings presents certain challenges. The ability to obtain castings with a fine-grained (high-strength) structure and a homogeneous composition throughout the entire volume of cast billets can be achieved by regulating the thermal regime of castings, for example, by combining suspension casting with the lost foam casting method. To introduce inoculants into the melt, the polystyrene model itself is directly used. The foundry is the most important procurement base of mechanical engineering. A variety of shaped castings are produced by casting, which are obtained by filling casting molds with liquid metal. During solidification, the metal takes on the shape of the cavity of the mold into which it was poured. Cast products are widely used in industry, as the sizes and shapes of castings often approach the required sizes and shapes of finished products to a greater extent than blanks obtained by other methods. This is a very important advantage, as reducing the cost of machining reduces the cost of products and reduces metal consumption. In addition, the production of cast blanks is much cheaper.

https://doi.org/10.48081/BGQF2236

2026

Issue 2

The paper presents a comprehensive study of the physicochemical properties of various types of chrome raw materials from Kazakhstan: chrome ore, chrome concentrate and chrome dust (CD), which is a waste product of gas cleaning systems in ferrochrome production. A comprehensive study of the chemical and phase composition, morphology and elemental heterogeneity of the materials under study was carried out using chemical analysis, X-ray phase analysis (XRD) and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). It was shown that chrome ore is characterized by a high content of Cr₂O₃ and MgO with a significant proportion of silicate impurities, chrome concentrate is enriched in chromium oxide and has a minimum content of SiO₂, and chrome dust contains a reduced amount of chromium and an increased content of silica and silicates. XRD revealed the presence of spinel phases (MgCr₂O₄, FeCr₂O₄) and Cr and Fe oxides, and SEM-EDS showed pronounced zonal chemical heterogeneity, especially in dust waste. The obtained results allow us to estimate the metallurgical value of the studied raw materials and justify the feasibility of recycling chrome dust in the technological cycle of ferrochrome production.

https://doi.org/10.48081/BGQF2235

2026

Issue 2

The article considers the use of heat-resistant and wear-resistant materials for internal combustion engine components in a hybrid vehicle. In such engines, the service life of a part is not determined only by its strength margin. Under real operating conditions, friction, heating, changes in clearances, surface quality, and frequent transitions between engine operating modes act at the same time. Therefore, the study focuses not on one parameter, but on several indicators that are closer to actual operation: friction coefficient, temperature resistance, thermal deformation, and estimated service life. Steel 40Kh, titanium alloys, Al₂O₃ ceramics, and Ni–SiC coatings were selected for comparison. Steel 40Kh was used as a basic reference material for comparison. Titanium alloys were considered from the standpoint of reducing the mass of parts, ceramics as a material for high-temperature zones, and Ni–SiC coatings as a protective layer for friction surfaces. The study used published data, simple calculation relationships, and simulation in ANSYS and SolidWorks. The obtained results show that the most practical approach is not the complete replacement of conventional materials, but their selective application according to load zones. With this approach, the estimated service life of ICE components may increase by about 30–35%. At the same time, these values require verification on a real engine or an engine test bench, since service life strongly depends on coating technology, lubrication, cooling, and operating conditions.

https://doi.org/10.48081/BGQF2241

2026

Issue 2

Hydraulic valves are integral components of hydraulic drive systems, performing the functions of regulating the flow rate and direction of the working fluid. Among them, proportional spool-type directional control valves stand out due to their high control precision and reliability, which ensures their widespread use in both industrial and mobile applications. However, one of the key challenges in their design remains the flow forces generated by the momentum exchange of fluid in the control orifices. These forces can cause undesirable spool deviations, reducing system stability, control accuracy, and energy efficiency. This study presents a theoretical and geometrical analysis of flow forces in proportional spool valves, aiming to transform them from a disturbing influence into a useful control parameter. A modified spool geometry is proposed that maintains an almost constant flow force throughout the entire stroke range. The effectiveness of the proposed approach is validated through analytical calculations and numerical simulations. The results obtained can be applied in the design of next-generation energy-efficient and high-precision hydraulic systems.

https://doi.org/10.48081/BGQF2213

2026

Issue 2

This article discusses in detail the design features of piston rings-the most important element in the structure of the cylinder – piston group, which is the main unit of internal combustion engines, their condition in operation and the impact on the energy, environmental and mechanical efficiency of the engine as a whole. In the course of the study, the main functional types of piston rings were analyzed: compression, oil-removing and double combined, and the influence of their geometric shape (barrel-shaped, conical, rectangular profiles), configuration of the side surface and modification of the contact surface on the degree of sealing and friction in the cylinder area was described. The influence of various materials used on the reliability of operation is shown: cast iron, alloy cast iron, steel-based rings and their wear-resistant coatings: chromium, molybdenum, nitride, plasma. At the same time, the results of a patent study of modern versions of compression rings were analyzed. Innovative solutions on the world's patent databases include thickness changes, special grooves that reduce thermoelastic deformation, low-friction concreting technologies, crack optimization, and design innovations that increase gas tightness. The analysis showed that an important role in improving the efficiency of internal combustion engines is played by improving the design parameters of piston rings. The main purpose of the scientific work is to identify ways to reduce friction and wear by optimizing the design of piston rings using modern materials and engineering methods, increasing the life of the cylinder-piston group and increasing the energy efficiency of the engine.

https://doi.org/10.48081/BGQF2245

2026

Issue 2

An earthquake simulator is a device for simulating ground motion during an earthquake and is designed to generate seismic waves. The earthquake simulator is used by emergency response personnel to conduct seismic training and to train them to respond to a real earthquake. At least hundreds of millions of people worldwide are at significant risk of catastrophic seismic damage. This problem is particularly acute in Almaty, where the last earthquake in the spring of 2024 caused panic among people and demonstrated a complete lack of preparedness for how to react and behave during an earthquake. Earthquakes pose a danger and risk to everyone, and everyone should be aware of the appropriate knowledge and protective measures. This study developed and manufactured a prototype earthquake simulator for training human behavior during earthquakes. This simulator is based on a flat parallel rope robot that simulates a real earthquake based on a given earthquake seismogram. The earthquake simulator, based on a planar cable parallel robot, performs translational single-axis movements in the X or Y direction. Experimental studies of the prototype earthquake simulator, based on a planar cable parallel robot, confirmed its ability to reproduce a given seismogram.

https://doi.org/10.48081/BGQF2216

2026

Issue 2