The low hardness of copper alloys used as the material for continuous casting molds makes them susceptible to plastic deformation, wear, and high-temperature oxidation. This leads to premature degradation of working surfaces and the formation of defects on the cast billets. In this study, the microstructure, phase composition, mechanical, and tribological properties of Cr₃C₂–NiCr coatings deposited by high-velocity oxy-fuel (HVOF) spraying onto copper substrates used in casting molds were investigated. The relevance of this research is driven by the need to increase the service life of copper molds in continuous steel casting processes. It was established that the HVOF spraying parameters significantly affect porosity, coating thickness, microhardness, and the tribological behavior of the coatings under conditions simulating contact between the billet and the working surface of the mold. Among the investigated regimes, the coating deposited at a powder feed rate of 11.39 m/s formed the densest lamellar structure and demonstrated the highest microhardness. Tribological tests showed that this coating exhibited the lowest coefficient of friction, whereas the other samples were characterized by higher porosity and poorer wear resistance. The obtained results highlight the importance of optimizing HVOF spraying parameters for the development of wear-resistant protective coatings capable of operating effectively on copper molds subjected to severe thermomechanical loads during steel casting.

https://doi.org/10.48081/BGQF2231

2026

Issue 2

In the context of accelerated digitalization, global decarbonization, and growing geopolitical uncertainty, the stability of supply chains for semiconductors and strategically important minerals is becoming key to the economic and technological security of States. This study is aimed at analyzing the structural vulnerabilities of global supply chains of critical resources and substantiating the potential of a data-centric approach as a tool to increase their resilience. The methodological basis of the research is the analysis of international statistical databases, industry analytical reports, as well as the use of a resource-based approach (Resource-Based View) in its extended network interpretation (network-RBV). It is shown that the high concentration of processing and technological capacities in a limited number of countries creates systemic logistical and institutional risks, while the availability of a raw material base alone does not provide sustainable competitive advantages. It has been established that Kazakhstan, with its significant potential for strategic minerals and advantageous transit and geographical location, remains primarily an upstream participant in global value chains. It is proved that the introduction of a data-centric approach based on the use of big data, the Internet of things and machine learning methods makes it possible to move from reactive to predictive supply chain management, increase their transparency and adaptability. It is concluded that it is advisable to form a data-centric logistics ecosystem in Kazakhstan that can transform the country's role in global supply chains from a supplier of raw materials to a regional analytical and logistics hub.

https://doi.org/10.48081/BGQF2246

2026

Issue 2

This article assesses the transport and logistics potential of the road transport complex in the western region of the Republic of Kazakhstan as a factor in the sustainability of freight transportation and integration into international transport flows. The empirical base is formed based on official statistics and materials for 2019–2024, as well as publications and reports of international organizations. The transport and logistics potential is revealed through a system of indicators characterizing the state of road infrastructure, the technical level of the vehicle fleet, the availability of logistics hubs, transportation efficiency, investment activity, and the level of digitalization of transportation management. An interregional comparative analysis, SWOT and PESTEL analyses were used to ensure a comparable interpretation of the data. A quantitative verification of the parameter dynamics was performed using correlation analysis (Pearson's coefficient) between investment volumes, the proportion of roads in satisfactory condition, and the volume of freight traffic. To substantiate the recommendations, forecast estimates for 2025–2030 were constructed using extrapolation and exponential smoothing methods (Holt's model). The approach to optimizing traffic flows is presented as a linear programming problem, allowing us to evaluate the effect of redistributing freight flows between key hubs while minimizing total transportation costs. The results obtained allow us to prioritize road and logistics infrastructure modernization, fleet renewal, investment policy, and the implementation of digital transportation management solutions.

https://doi.org/10.48081/BGQF2243

2026

Issue 2

The paper presents the results of a comprehensive study of wear and corrosion resistant oxide coatings based on Al₂O₃, obtained by air-plasma spraying, designed to increase the service life of pumping equipment parts operating in aggressive and abrasive environments. Austenitic stainless steel 10Kh18N9, widely used in chemical and power engineering, was used as the substrate material. The main focus is on studying the influence of plasma arc current in the range of 300–500 A on the formation of microstructure, phase composition, porosity, as well as mechanical, tribological and adhesive characteristics of sprayed coatings. It has been shown that increasing the spraying current promotes more complete melting of Al₂O₃ powder particles, improves their flattening upon impact with the substrate surface, and forms a denser and more uniform coating structure with reduced porosity. It has been established that with an increase in the plasma arc current, an increase in the adhesive strength and microhardness of the coatings is observed, as well as a decrease in the coefficient of friction and wear intensity under abrasive conditions. The most favorable combination of high wear resistance, adhesive strength and structural stability of coatings is achieved with a spraying current of 500 A. Corrosion tests in aggressive environments have shown that the application of Al₂O₃ coatings does not have a significant negative impact on the corrosion behavior of 10Kh18N9 steel and does not reduce its corrosion resistance. The obtained results confirm the potential of using air-plasma oxide coatings based on Al₂O₃ for the protection and strengthening of pumping equipment parts operated under conditions of intensive wear and corrosion.

https://doi.org/10.48081/BGQF2226

2026

Issue 2

Earthworks are key and the most extensive operations in the construction of roads, airfields, and industrial sites. They are performed by earthmoving machines, including bulldozers of various traction classes and blades of various designs. This work is devoted to finding and combining the advantages of different blades, such as spherical and semi-spherical, calculating their efficiency according to specific indicators, and experimentally confirming the rationality of this combination. The paper briefly considers the influence of the blade visor angle on the behavior of the soil chip and its loss into side rollers, since in known recommendations the blade profile parameters ensure soil collection and movement without the visor's involvement. The study hypothesizes that to reduce the friction forces of the soil against the blade, the visor should have the capability to change its installation angle. The paper also presents the results of experimental studies of the digging process with a blade that changes its cutting angle during operation. The research related to the publication is funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan - grant AP22684640 – "Development of an articulated design of a bulldozer blade with a multi-level geometry change". Keywords: soil cutting, bulldozer, blade, spherical blade shape, soil drag prism, cutting resistance forces.

https://doi.org/10.48081/BGQF2214

2026

Issue 2

This paper presents a review and conceptual design justification of a mechanical press with a combined cam-screw actuator and a bottom-mounted drive. A comparative analysis of existing press equipment is conducted in order to identify the limitations of traditional crank, screw, toggle, and eccentric press designs. Based on this analysis, a conceptual layout of a cam-screw mechanical press with a lower drive arrangement is proposed as a promising direction for further engineering development. The paper discusses the possibility of using a cam profile to provide smoother tool approach to the workpiece and to reduce impact interaction during the initial stage of deformation. The proposed approach is considered at the conceptual level and forms the basis for further development of a detailed kinematic and dynamic model. Preliminary conceptual analysis indicates that a cam-screw press with a bottom-mounted drive may provide improved maintenance conditions, reduced impact loads, and better dynamic stability due to the lower location of the main drive components. The bottom-mounted drive is a strategic design solution that increases stability (vibration resistance), improves maintenance (drive units are within easy reach), and keeps the work area clean, as gearbox oil does not spill onto the workpiece. The proposed layout may contribute to reducing the overall press height and metal consumption; however, quantitative confirmation of these advantages requires further engineering calculations, numerical simulation, and experimental validation. The research results can be used in the design of next-generation high-precision cam-and-screw equipment, particularly for precision blanking, calibration, and micro-stamping equipment.

https://doi.org/10.48081/BGQF2230

2026

Issue 2

This study investigates the effect of process parameters and shielding gas composition on the microstructure formation of stainless steel 308LSi by Wire Arc Additive Manufacturing (WAAM). The experiments were carried out using a 0.8 mm welding wire and a gas mixture of 80%Ar + 20%CO₂. The deposition parameters of I = 110 A, U = 20 V, wire feed speed of 400 mm/min, and interpass dwell time of 60 s ensured a stable formation of a cylindrical specimen without pronounced defects. Microstructural analysis revealed an austenitic (γ) matrix with uniformly distributed δ-ferrite. Three characteristic δ-ferrite morphologies were identified: vermicular, skeletal, and lathy, which is consistent with published data for WAAM 308L deposits. Detected micropores were local and did not significantly affect structural integrity. Microhardness measurements showed a stable range of 191–213 HV1, confirming a homogeneous structure and the absence of localized hardening or overheating. It was established that the selected process parameters provide samples with a stable dual-phase γ + δ structure, a minimal amount of defects, and stable mechanical properties.

https://doi.org/10.48081/BGQF2222

2026

Issue 2

When processing copper-molybdenum ores, the main objective is to extract copper at the initial stage of enrichment using bulk-selective flotation. This prevents overgrinding and loss in tailings. The aim of this study is to improve copper-molybdenum ore processing technology by establishing optimal parameters for copper and molybdenum extraction during bulk flotation with the extraction of the total mass of sulfides (copper + molybdenum + pyrite), separating them from gangue, and subsequently recovering first-stage copper concentrate. Preliminary experiments revealed that the optimal consumption of collecting reagent (SIBX) is 80 g/t. These experiments demonstrated that primary flotation can be carried out by separating the primary copper concentrate at the first stage, since commercial copper concentrate can be obtained within the first minutes (the first three minutes of the flotation process) of the process. A concentrate with a copper content of approximately 30% and a recovery of 89% was obtained. It was found that with selective separation of concentrate in an open cycle during copper extraction in the first cycle, it is possible to obtain molybdenum concentrate with a molybdenum content of ≈ 0.9% and an extraction of 57.7%. In the future, it is planned to study the closed cycle of flotation enrichment of copper-molybdenum ore and metallurgical processing of the obtained concentrates.

https://doi.org/10.48081/BGQF2237

2026

Issue 2

This paper presents the results of large-scale laboratory ferrosilicon smelting in an 80 kVA ore-thermal furnace using recycled man-made materials. The possibility of partially replacing steel chips with iron ore agglomerate obtained from ferrous sands of alumina production, as well as the use of aluminum slag-based pellets, is investigated. The influence of the chemical composition of the charge components on the physicochemical and electrical characteristics of the smelting process is determined. It is shown that increased SiO2 and Al2O3 contents in the pellets promote the formation of silicate melts, stabilization of the slag phase, and improved conditions for silicon reduction. The identified kinetic patterns allow for temperature optimization. The developed technology also contributes to a significant reduction in energy consumption. It is determined that the use of recycled resources reduces the content of harmful impurities in the alloy and reduces production costs. The obtained results confirm the technological efficiency and environmental feasibility of using complex man-made materials in ferrosilicon smelting.

https://doi.org/10.48081/BGQF2234

2026

Issue 2

This article discusses the structural features, operating conditions and reliability indicators of utility vehicles used for the collection and transportation of solid household waste (MSW). Construction of garbage trucks were considered as a complex technical system, and the factors contributing to the failure intensity and operability of their main elements were analyzed. During the study, the resource of a garbage truck was considered as a two-module system consisting of the main vehicle and special equipment, and the impact of the intensity of use of special equipment on the overall resource of the machine was evaluated. Based on probabilistic models of reliability theory, the average mileage between failures, repair and maintenance costs were determined. The results obtained make it possible to optimize the frequency of technical impact of garbage trucks, reduce the risks between planned repairs and emergency failures, as well as increase the efficiency of technical operation at utility enterprises.

https://doi.org/10.48081/BGQF2247

2026

Issue 2