The purpose of the work is to establish how the composition, morphology, local elemental heterogeneity, particle size distribution, and technological properties of industrial powder mixtures influence their suitability as cobalt-free metal bonds for diamond-containing tool materials intended for stone processing. Commercial powders were used to prepare cobalt-free metal powder mixtures of the Cu–Sn, Cu–Sn–Ni–Fe, and Cu–Sn–Fe–Fe(carb)–Zn–Ni systems. The elemental composition of the mixtures was determined by X-ray fluorescence analysis. Particle morphology and local elemental distribution were studied by scanning electron microscopy and energy-dispersive X-ray spectroscopy, including Quant and Phase mapping. Particle size characteristics were evaluated from SEM images using ImageJ software, with the Feret diameter as the particle-size parameter; the distributions were described using the percentiles d10, d50, and d90, as well as the Span value. The bulk density was determined using a 25 cm3 measuring cup, and the flowability was evaluated as the corrected flow time through a calibrated funnel. Additional SEM/EDS observations were performed for a selected diamond-containing composition based on the Cu–Sn–Fe–Fe(carb)–Zn–Ni system The investigated powder systems differ substantially in particle morphology, local chemical heterogeneity, particle size distribution, and technological behaviour. The Cu–Sn system is characterised by a predominantly Cu-rich matrix with localised Sn-rich regions. The Cu–Sn–Ni–Fe system exhibits the broadest particle-size distribution, the highest degree of polydispersity (Span = 2.13), and the poorest flowability. The Cu–Sn–Fe–Fe(carb)–Zn–Ni system exhibits the highest local compositional complexity but also the most compact particle-size distribution (Span = 1.22), along with a comparatively favourable combination of high bulk density and acceptable flowability. Diamond addition decreases bulk density and worsens flowability across all investigated systems; however, the Cu–Sn–Fe–Fe(carb)–Zn–Ni composition retains comparatively favourable technological characteristics among the powder mixtures investigated. The present study focuses on the characterisation of powder mixtures before consolidation and does not include analysis of the sintered microstructure, mechanical properties, or tool performance under service conditions. Further work should therefore be directed toward sintering behaviour, microstructure formation in the consolidated bond, and performance testing of diamond-containing materials during stone processing. The results obtained enable comparative assessment of candidate cobalt-free powder matrices for diamond-containing compositions and optimisation of powder mixture preparation based on composition, particle morphology, particle size distribution, and technological properties. A comparative analysis of cobalt-free powder mixtures for diamond-tool metal bonds was conducted using a unified approach that combined XRF, SEM/EDS Quant and Phase mapping, particle size analysis, and technological testing. It was shown that the most compositionally complex system, Cu–Sn–Fe–Fe(carb)–Zn–Ni, provides the most balanced set of structural and technological characteristics and is therefore the most promising powder matrix among the investigated systems.
Many uncrewed aerial vehicle (UAV) navigation systems rely heavily on Global Positioning System (GPS) and Inertial Measurement Unit (IMU) measurements, which may suffer from noise, drift, or temporary degradation. This study aims to improve UAV localisation performance by evaluating an Extended Kalman Filter (EKF)-based multi-sensor fusion framework that combines GPS, IMU, and radar measurements under a controlled simulation environment. An EKF-based state-estimation framework is implemented to fuse measurements from multiple sensors to localise a UAV. Rather than proposing a new EKF formulation, the study compares five sensing configurations: GPS-only, radar-only, GPS+IMU, GPS+radar, and GPS+IMU+radar. Simulated UAV trajectory data are generated in MATLAB using a predefined figure-eight path, and localisation performance is assessed using the Root Mean Square Error (RMSE) metric. The results show that all multi-sensor configurations improve localisation accuracy compared with the single-sensor baselines. Among the evaluated cases, the GPS+IMU+radar configuration achieves the best performance, with an average point-to-point error of 0.11 m, while the radar-only case yields the largest error of 0.84 m. The results indicate that integrating complementary sensors into the EKF framework can improve estimation accuracy and yield more consistent localisation performance under the simulated conditions examined in the given study. The validation is limited to simulation-based experiments using a single representative trajectory and predefined sensor parameters. Therefore, the findings should be interpreted within the scope of controlled test conditions. Future work should examine more challenging scenarios, including measurement disturbances, sensor dropouts, bias effects, multiple trajectory patterns, and real-time or real-world flight validation. The study provides a practical reference for selecting sensor combinations in UAV navigation systems by highlighting the trade-off between localisation accuracy, system complexity, and implementation cost. In particular, GPS+IMU+radar offers the highest accuracy in the present study, while GPS+radar provides a useful balance between performance and system complexity. The contribution of this work lies in a systematic comparative evaluation of five sensor configurations within a unified EKF-based UAV localisation framework. The study offers application-oriented insight into the relative performance of GPS, IMU, and radar combinations and clarifies the practical benefits of tri-sensor fusion under a common simulation setting.
Study of the impact of key determining factors, in particular the rate of nitrogen injection and the number of injection wells (one or three wells), on the final gas recovery factor and the gas recovery factor for residual gas. Using the Petrel & Eclipse software package, two scenarios for displacing residual gas with nitrogen from a depleted gas field were investigated. In the first scenario, nitrogen was continuously injected into the field at different rates into a single injection well located in the centre of the field. The ratio of the nitrogen injection rate to the current natural gas production was 1, 1.25, 1.5, 1.75, 2, 2.5. In the second scenario, continuous nitrogen injection into the deposit was carried out at different rates (1, 1.25, 1.5, 1.75, 2, 2.5) into three injection wells (one central well and two production wells, one and three, were converted into injection wells). The results of the studies are presented in tables and graphical representations of the studied parameters. According to the results of studies under the scenario of one injection well with an increase in the degree of compensation of current natural gas production by nitrogen injection Qn/Qg from 1 to 2.5, respectively, the total gas recovery factor βg decreases from 95.15 to 93.57%, the residual gas recovery factor βres decreases from 51.09 to 35.19%, and the duration of deposit development decreases from 305 to 191 days. In scenario two, with three injection wells and an increase in Qn/Qg from 1 to 2.5, βg decreases from 95.80% to 94.44%, βres decreases from 57.66 to 43.93%, and the term of deposit development is reduced from 329 to 250 days. The highest gas recovery factor for the deposit is obtained with three injection wells. The limitation of the study is the use of a simplified hydrodynamic model of a depleted gas reservoir with homogeneous filtration and storage properties (porosity and permeability). Real geological structures may be characterised by tectonic disturbances and lithological variability, which will significantly affect the formation of the nitrogen-natural gas mixing front and the rate of nitrogen breakthrough into production wells. The research results have direct practical applications in the design of technologies for recovering residual gas from depleted fields. The obtained dependencies enable us to determine the optimal number of injection wells and nitrogen injection rates to achieve the maximum gas recovery factor while minimising development time. The results of modelling in the Petrel & Eclipse software package serve as the basis for developing design solutions for modernising production systems in the late stage of field operations. The study is original because it is the first comprehensive analysis of the relationship between the number of injection wells and the degree of compensation of current production by nitrogen injection for depleted gas fields.
The internal combustion engines are a highly widespread technology in the transport sector, with an approximate of 1.4 billion vehicles in circulation in the world now. Although earlier studies had examined the influence of the reaction forces, gas pressure, torque and the friction force on the response of the reciprocating internal combustion engine, independently, the study offers a new analytical model that combines all these factors to demonstrate its impact on the engine. The research utilises mechanical analysis to identify critical issues in dynamic analysis and engine design. The reaction forces on the crankshaft and the torque exerted are measured through an analysis of kinetics and free-body diagrams of a reciprocating engine system. Moreover, the ANSYS Workbench was used to model the nonlinear static response to rough contact conditions and provided more profound knowledge of the dynamics of engine operations. Comparative findings indicate significant differences of up to 36, 15 and 34 per cent in the reaction force along the x-axis, y-axis and friction forces, respectively, between the actual analytical and point-mass approximate calculations. ANSYS Workbench nonlinear static simulation revealed areas of critical stress and a peak displacement of about 16.7 mm, which provides useful information about improving the design of the engine. The study was limited to reciprocating engines. The effect of thermal stress was also not considered. The paper is a combination of reaction forces analysis in x and y axes, torque, friction forces and gas pressure to analyse their combined effects on internal combustion engines. The novelty of the study lies in its integrative methodology, which enables a strictly quantitative assessment of the joint action of multiple forces. Moreover, ANSYS Workbench is used to implement the nonlinear static response modelling during rough contact conditions, which also gives a more complete picture of the dynamics of the engine in a real-world setting.
The purpose of the study is to investigate the fracture toughness and total fracture work of some materials that can be used for complete denture fabrication using Masked stereolithography 3D printing technology and the conventional lost-wax technique. Three specimen groups were fabricated. Two of them were 3D-printing using Masked SLA technology with two suitable, commonly used denture base resins. The third group was made of heat-curing acrylic resin by the conventional lost-wax technique. A crack was created on each specimen. The prepared objects were tested using a three-point flexural test, and the collected data were used to calculate fracture toughness and total fracture work. The results reveal that the mean value of maximum stress intensity factor (Kmax) was reached by the heat-curing resin (1.65 MPa m1/2 0.18), followed by 3D-printed specimens with Kmax between 1.07 MPa m1/2 0.08 and 1.43 MPa m1/2 0.09. The heat-curing acrylic resin also has the highest capacity for load bearing before fracture, as the obtained mean values for total fracture work (Wf) were 2.8 kJ/m2 0.85, followed by the CAD/CAM resins by 1.7 kJ/m2 0.4 and 1.3 kJ/m2 0.2. The limitations of the study concern the additional clinical factors. They should be observed to enable a more detailed evaluation of the mechanical properties of the observed materials. The denture base design should be planned according to the specific anatomical features of each edentulous patient. It could be the reason why some dentures break, and others don't, even if they are made of the same material and thickness. Complete dentures still play an essential role in a clinician’s treatment plan. Knowledge of the mechanical properties of different denture base resins is very valuable for proper material selection and approach to complete denture fabrication. The current study reveals that the examined denture base resins for 3D printing have lower mechanical properties than the conventional heat-curing resins. The fracture toughness and total fracture work of the tested resins for 3D printing could result in more susceptible to fractures complete dentures than those made of the heat-curing resin. Nowadays, there is a huge variety of materials and approaches for complete denture fabrication. Knowledge of denture base resin properties is very important for the proper selection of a material and/or technology for each clinical case.
The paper aims to study and statistically analyse the influence of the GMAW process parameters (arc voltage, welding current, and welding speed) on the angular distortion in the DIN 17100 St37 steel plates and profiles. In the study, the design of experiments (DOE) method was implemented using the Taguchi L9 orthogonal array. Arc voltage, welding current, and welding speed were selected as control factors, and angular distortion was selected as the response. The 2 set-nine experiments were designed for plate and profile joints, and the angular distortion was measured for each. In this research, a statistical analysis was conducted using Minitab 16. Among the parameters, welding current was the most significant, contributing 56.68% & 72.9%, whereas arc voltage had the least impact, contributing 10.38% & 0.71%. The angular distortion value varied from 8 to 13.8 for plates and from 5 to 9.8 for profiles in the study. The paper was based on the GMAW process, which is widely used in the automotive industry. Future research could consider the effect of FCAW, GTAW, and SAW process parameters on angular distortion. In addition, St37 steel, a common carbon steel, was used in this paper, while St52 and St44 steels can be used for future studies. The findings of the paper have important practical implications for the automotive industry. In the design and production of steel structures, it is very important to control and reduce angular distortion in welded joints. Because angular distortion causes dimensional errors and increases the effort and cost of structure modification. There is relatively little information on the statistical analysis of angular distortion in low-carbon steels, and most research is purely experimental. In addition, there is very little literature on the angular distortion of steel profiles. Welding steel profiles is widely used in automotive manufacturing. The results of this research can be used to control and reduce angular distortion in welding joints of low-carbon steels.
The aim of the work is to develop a business model for a startup related to the creation of a system supporting the strength of upper limbs for elderly and disabled people. The planned company will utilise the fashionable and constantly evolving 3D printing technology, combined with significantly easier control of electric motors using increasingly popular microcontrollers. Based on available technological knowledge from the electronics, automation, and IT sectors, the product in question has been proposed and characterised. Then, the company’s strategy, the product’s market launch, and a forecast for the success of the entire project have been determined. The article includes a technical description of the device under development, including its physical components, software, sensors, and electronic devices. A business analysis, including market and environmental analyses, that defines the target customer group and their preferences, is also discussed. The largest target group for the proposed system will be older adults who experience difficulties performing even the simplest tasks, such as lifting and carrying objects. The device can also be used for rehabilitation purposes or to relieve pressure on a joint, muscle, or bone weakened by an injury. In this case, the target group – although significantly smaller – will be younger people, i.e., those of working age. Exoskeletons and similar products have business potential in the medical industry due to an ageing population – the number of target recipients for the proposed product will increase in the coming years.
The paper aims to identify, based on a literature review, the factors influencing emissions in the Fused Deposition Modelling (FDM), also known as the Fused Filament Fabrication (FFF) process. We carried out a literature review using the PRISMA methodology. Then, we randomly selected 13 articles using a Python script that implements the Fisher-Yates shuffle algorithm to minimise bias. The filament type affects both particulate matter and VOC emissions. Its physical form (pellets, pulverised,…) and chemical composition (colour pigments, dyes, flamant retarding additives, metal and mineral fillers,…) influence the types of compounds released, as well as the level of emissions. Besides, the extruder temperature affects the emission rate of PM and its concentration. The degree of impact varies depending on the filament type and its composition (additives, stabilisers, plasticisers, etc.). * To determine the optimal printing settings (e.g., extruder temperature, nozzle diameter) that ensure low emission levels without any part quality compromise; * To identify the critical temperature threshold where emissions augment exponentially; * To investigate the influence of the extruder's temperature on the concentrations of VOCs. The findings highlight the importance of selecting low-emitting materials such as PLA and optimising the extruder temperature and nozzle diameter to mitigate the release of harmful compounds during FDM printing. Industrialists as well as home hobbyists can use this information to potentially enhance workplace safety. Also, a suggested multi-layered strategy, founded on the synergy between engineering measures (enclosing the FDM printer with integrated filtration and ventilation systems), prioritising low-emission materials, and a collection of administrative safeguards. We proposed a multi-level emission mitigation strategy based on this parameter review and results from other studies.
The aim of the study is to demonstrate that SLS/SLM 3D printing of titanium alloys used for manufacturing prosthetic restorations constitutes a genuine process and material eco-innovation compared to CNC milling. The article develops the authors’ original Dentistry 4.0 concept, in which CBCT diagnostics, CAD design, digital twin, CAM technologies, and additive manufacturing of metallic structures form an integrated model of cooperation among the dentist, dental engineer, and manufacturing centre. Material consumption, buy-to-fly ratio, material costs, total costs, tool consumption, and the potential for reuse and recycling of material according to the 6R principle were compared. The results indicate that, in the analysed variants, CNC technology required 6 to 11 times as much raw material mass as SLS/SLM technology, with the greatest differences observed for full-arch implant-supported constructions. The analysis was carried out for selected types of prosthetic constructions, including three-point bridges and full-arch restorations supported on teeth or implants. The study also questions the legitimacy of using CNC for manufacturing prosthetic and implantological restorations in the context of excessive consumption of scarce critical materials, presenting a useful, real alternative in the form of SLS/SLM 3D printing using atomisation as a method of full recovery of the used material. The results confirm that SLS/SLM of titanium alloys is not merely an alternative manufacturing method but an eco-innovation that changes the production paradigm of prosthetic restorations from subtractive, waste-generating, and tool-intensive technology to additive, resource-efficient, digital, and circular technology.
The purpose is to establish dependencies between chemical and phase composition in the Ni-Al-Cr-Co-W-Mo-Ti-Nb-Ce-Zr-B-La system; obtain dependencies between the mismatch of crystal lattices of the strengthening phase and matrix; obtain dependencies between phase composition and mechanical properties to increase the service life of hot-tract parts.The methodology for obtaining the dependencies involved simulating the thermodynamic processes of phase formation, where the elements were changed step by step using the CALPHAD thermodynamic modelling method. Predictive calculations were performed based on the initial chemical composition of the VZhL-12 alloy, which determined the most probable phases and their corresponding chemical compositions. The phase composition was experimentally determined using a REM-106I scanning electron microscope with an energy-dispersive X-ray spectral microanalysis system. The method was employed to investigate the morphology and chemical composition of the precipitated phases within the alloy structure.The influence of individual alloying elements on phase stability has been established: aluminium promotes the formation of the γ′-phase, reaching its content of up to 89% at 7.6% Al, but when in excess, it causes the formation of brittle TСР phases, which impair ductility; titanium also increases the content of the γ′-phase, but when the content is above 6.4%, it leads to the formation of lamellar TСP phases (for example, the η-phase), which negatively affect the mechanical properties; cobalt and chromium increase their concentration in the strengthening phase, promoting its thermal stability. Molybdenum and tungsten do not directly participate in the formation of the γ′-phase but increase its heat resistance. The effect of temperature on the lattice parameters of the γ and γ′-phases is shown. The minimum mismatch of the lattice parameters (-0.4%) is observed at 700-800C, corresponding to optimal values of strength, ductility, and creep resistance. Experimental testing on the industrial single-crystal alloy VZhL-12 yielded good agreement between the calculated and actual data.The established patterns of alloying, phase transformations, and thermomechanical properties can serve as the basis for creating new generations of materials capable of operating under extremely high temperatures and loads. However, the disadvantages of this method include sensitivity to the initial data, the ability to analyse materials only in a stable state, and the reliability of thermodynamic databases (which have recently improved significantly). Future studies are planned to study the behaviour of secondary phases and the influence of rare earth elements in the system.The obtained relationships between alloying, phase transformations and thermomechanical properties can be used to create new generations of materials. They enable the determination of properties of new alloys without testing, significantly reducing research costs. The work will also be beneficial in refining the existing chemical compositions of alloys.The work is intended for researchers and engineers in the field of high-temperature materials (superalloys).
Humidity has a negative effect on the 3D printing quality of polyamide 12 (PA12) components. The influence of humid powder on 3D printed materials has been the subject of several investigations. Nevertheless, there has been limited investigation into how process variables affect the moisture content of 3D parts. Therefore, the work investigates the impact of processing parameters, such as layer thickness and laser power, on the humidity content of 3D-printed PA12 specimens.The humidity rate was determined by comparing the mass change percentage before and after the oven test, in accordance with ASTM standard D6980.Consequently, the humidity rate is reduced because higher heat is generated by an enhanced laser power ratio, particularly at lower layer heights, which evaporates any remaining moisture during sintering. On the other hand, a thinner layer reduces humidity by keeping moisture out of the print output. Combining the effects of laser power and layer thickness reveals that configurations with a low laser power ratio and an elevated layer height are associated with higher humidity rates. Therefore, compared with layer height, laser power has a greater impact on humidity rate, according to ANOVA analysis.Overall, this experiment demonstrated the role of changing process variables in lowering moisture content and suggested future studies to understand better the combined impact of humidity on their mechanical and porosity properties.The originality of the study lies in the examination of how processing parameters, including laser power and layer thickness, affect the moisture content of PA12 manufactured parts.
Tissue engineering has been studied extensively recently due to the need for replacements for damaged body parts. The tissue regeneration process must be characterised by a high proliferation of cells in the diseased part. The materials must be compatible with the body tissues and can perform bio functions. In addition, it has a controlled degradation rate inside the body.In the current research, chitosan was chosen due to its biological properties and biocompatibility. Genipin was added to achieve cross-linking of the chitosan chains to obtain a different degradation rate. The chemical blowing agents were applied to create a porous structure that allows the growth of body cells and tissues through it.The FTIR test results showed that crosslinking occurred between the chitosan and genipin, which was reflected in the thermal behaviour of the mixture through the DSC examination. The results showed a decrease in the degree of decomposition of about 5.76% due to the chemical bonding between amine groups in chitosan with genipin. The degradation test showed a decrease in the weight loss by 51.28% with an addition of 0.5% genipin and a period of immersion of 6 weeks due to cross-linking. The samples showed good antibacterial properties with the addition of ZnO.The prepared tissues require specific properties to achieve the goal, such as biocompatibility and a controlled degradation rate, in addition to the size and per cent of porosity that allows the growth and proliferation of cells through it. It can be achieved through the proportion of additives and the control of preparation conditions.Through the results, tissues can be manufactured with bioproperties; due to the materials used in tissue preparation being extracted from natural sources, it is biocompatibility and non-toxic. It can be implanted inside the body for many applications, such as bone regeneration.Tissue preparation with a different rate of deterioration, and by using the chemical blowing ageing method, different porosities were obtained in terms of ratio and size, and all this qualifies the tissues for different medical applications.
The aim of this work was to critically evaluate the materials available for the production of prosthetic and implantological restorations and to select the optimal material in terms of selected functional and technical characteristics, along with conducting strength tests (bending and tensile) and determining the Young's modulus for the material chosen, i.e., the Ti6Al4V alloy.This study employed procedural benchmarking methods to create a dendrological matrix, assessing the potential and attractiveness of each material and manufacturing technology. To verify these assumptions, samples of Ti6Al4V Eli Grade 23 powder were 3D printed (SLS) and subjected to strength tests to empirically verify the theoretical assumptions available in the literature for components manufactured by casting and milling technologies.The analysis confirmed that the Ti6Al4V alloy meets all the requirements for materials proposed for dental implants and prosthetic restorations. This material stands out for its exceptional attractiveness and potential compared to other materials analysed, such as zirconia, Grade 4 titanium, Ti-6Al-7Nb alloy, and PEEK-based composite materials. Further analysis compared the technologies used to produce implant-prosthetic components from the Ti6Al4V alloy. 3D printing (SLS/SLM) proved to be the technology with the highest utility value, in line with the Dentistry 4.0 concept. The flexural strength of the printed samples was higher than that of the milled and cast samples. Even samples with lower flexural strength were able to withstand forces twice as high as the biting forces associated with extreme bruxism. Tensile strength values reached 875 MPa, while the Young's modulus reached nearly 99 MPa. In a key parameter for prosthetic components and implants, the material achieved an average bending test result of 1875 MPa.The described research results are part of a larger research plan, which includes conducting a complete FEM and empirical analysis for specific implant and prosthetic solutions to develop limiting parameters for the use of selected materials while maintaining the required strength under all occlusal conditions. Extended strength tests are also planned, including on samples with complex geometries, such as dental bridges. These results will be compared with available results from components manufactured using other technologies, such as casting and CNC milling.This article demonstrates the importance of implementing innovative treatment techniques using innovative materials and technologies, particularly those based on the Dentistry 4.0 concept, which supports the objectives of Industry 4.0. It also highlights how, as this transformation progresses, the demand for dental engineers with comprehensive knowledge and technical skills that complement the competencies of dentists implementing prosthetic and implant treatment plans in line with the objectives of Dentistry 4.0 will increase.
The objective of the study is to develop software for analysing the performance characteristics of individual technological facilities of underground gas storage (UGS) facilities. The software will determine the forecasted performance indicators and operating modes of gas storage facilities.The paper provides an in-depth analysis of the technological processes involved in withdrawing and injecting gas from/into underground gas storage facilities. Following an analysis of the initial data from the technological equipment, a database structure was developed and created. The software provides an object-by-object analysis of performance characteristics for individual technological units of gas storage facilities, enabling users to determine their predicted performance indicators, technological limitations, and optimal operating modes. Modules were developed to collect, process, and view data, as well as perform the necessary calculations.Based on the results of the work carried out, specialists will be able quickly to solve problems related to determining the forecast indicators of operation of UGS facilities and conduct an object-by-object analysis of their operation mode to identify the least efficient sections of the technological scheme in terms of hydraulic efficiency and productivity in different operating modes.To enhance the efficiency of UGS operations, it is recommended that the necessary software be implemented to calculate the predictive modes of operation of UGS technological units and to create a catalogue of their performance characteristics.The results of the work carried out allow specialists to create design schemes for UGS facilities that provide the ability to conduct a detailed, facility-by-facility analysis of the performance characteristics of individual process units. The analysis allows users to determine the forecast performance of both individual process facilities and UGS facilities as a whole.It is proposed that software be developed to determine UGS modes, considering the performance of the relevant technological equipment. Applying the approach ensures the efficiency of analysing UGS modes and selecting the optimal one.
The paper examines mechanically alloyed and spark plasma sintered FeCrAl-based ODS alloys with different amounts of titanium additions in terms of their potential application in gas-cooled fast nuclear reactors (GFRs). The research aims to elucidate how Ti addition influences the alloys’ microstructural properties and focuses on the microstructural stability characterisation and mechanical properties evaluation of the FeCrAl-ODS alloys at high temperatures up to 800C.In the given study, two compositions of FeCrAl ODS alloys with fixed 9% chromium, 5% aluminium, 0.3% yttrium oxide, and different titanium additions 0.5% and 1%, were mechanically alloyed (MA). The powders were then consolidated via spark plasma sintering (SPS) technique at 1050C, 40 MPa for 10 minutes and finally annealed at 1020C for 30 minutes. The resulting bulk materials were characterised for their microstructure and chemical composition using SEM-EDS and EBSD. Density measurements were conducted using Archimedes’ principle, while mechanical properties were evaluated through Vickers microhardness tests and tensile testing of the miniaturised samples in the range from RT to 800C.The successfully synthesised FeCrAl-Y2O3-Ti ODS alloys achieved a density of approximately 96% and a fine α-ferrite microstructure with most grains under 1 μm. Microstructural analysis revealed α-ferrite grains and the presence of nano- and micro-scale oxide and carbide precipitates. These are expected to stabilise the microstructure and enhance high strength at creep conditions and radiation resistance. Due to mechanical alloying, the crystallite size significantly decreased to about 50 nm, indicating adequate processing conditions. Additionally, the addition of titanium was found to improve the formation of complex oxides and carbides. Moreover, samples with a higher Ti content showed a higher ultimate tensile strength and yield strength at temperatures up to 500C than those with a lower Ti content. Therefore, it seems that Ti positively impacts the strength of the FeCrAl-Y2O3-Ti ODS alloys, and it is entirely consistent with the hardness results that also reveal higher hardness of the sample with higher Ti content.In FeCrAl-Y2O3-Ti ODS alloys, the oxide particles in the matrix should also significantly reduce the effect of ageing embrittlement at elevated temperatures and improve the stability of the microstructure by reducing grain growth under high-temperature operating conditions, thereby positively affecting the strength of the alloys. The results confirmed the homogeneous distribution of complex nanoscale oxide particles and thus improved mechanical properties. Notably, yield strength and tensile strength decrease with increasing test temperature, which was expected, and for samples above 500C and up to 800C, yield strength and tensile strength are almost the same (within the limits of measurement error). Plastic deformation at fracture is similar in both samples (about 10%) up to 500C. Above 600C, plastic deformation generally increases with increasing test temperature, up to about 50% for samples with lower Ti content at 750C. Although both samples show similar strength in the temperature range from 500C to 800C, the higher Ti content appears to reduce ductility.The main research primarily involved the development of new samples of FeCrAl-based materials with yttrium and titanium oxide additives to assess the feasibility of the designated alloys and their processing for further use in Generation IV reactor technologies. The results suggest that the application of the oxide dispersion enhancement effect can significantly increase the strength of FeCrAl alloys, thus qualifying them as materials potentially suitable for the manufacturing of components and subassemblies used under extreme operating conditions in high-temperature or gas-cooled fast nuclear reactors, including, for example, fuel claddings and hot ducts elements.Oxide dispersion strengthened (ODS) alloys, especially those based on FeCrAl, are recognised for their superior high-temperature strength and irradiation resistance, making them promising candidates for structural components in Generation IV nuclear reactors. Despite their potential, detailed experimental data on their mechanical behaviour at elevated temperatures remain limited, particularly for alloys processed by mechanical alloying and spark plasma sintering (SPS). The study provides new insights into the microstructural characteristics and high-temperature mechanical performance (up to 800 C) of miniaturised FeCrAl–Y2O3–Ti ODS alloy specimens. The originality lies in the specific combination of alloy composition, processing route, and advanced testing methodology, enabling the initial verification of the material’s behaviour under its intended operating conditions. The results contribute to a deeper understanding of how such materials perform in environments relevant to advanced nuclear systems, thus supporting the future application of ODS alloy components.
The study investigates the effect of directional anisotropy on the mechanical properties of a forged steel crankshaft. Finite element analysis was conducted to determine the most efficient mechanical strength and safety factor related to directional anisotropy.Comprehensive experimental analyses, including tensile testing, hardness measurements, chemical composition analysis, and microstructural observation, were conducted on specimens extracted from the crank webs. The specimens were designed to be specified at 0, 45, and 90 directions, respectively.The mechanical results of ultimate tensile strength and yield strength obtained in the 0 direction showed the highest value, while the 90 direction showed the lowest values. The maximum variation gap was 9.1% of ultimate tensile strength and 7.8% of yield strength. The distribution values of hardness results showed a narrow variation in all specimens. The microstructure was observed using an optical microscope, revealing no significant differences in phase structures among all specimens. A scanning electron microscope showed a fracture phenomenon. The specimens of 45 and 90 directions showed both dimple and cleavage patterns. In addition, the finite element simulation results showed that the critical location on the crankpin geometry was at the web fillet area due to the highest stress, which resulted in a violation of the Von Mises stress criterion. Attention should be paid to optimising material design for enhanced safety.The influence of directional anisotropy on the mechanical properties of forged steel crankshafts remains limited by its focus on in-house expertise in the manufacturing process, which may not accurately represent all crankshaft designs or materials. Future research should explore a broader range of forged steel grades, conduct preliminary stress analysis, and examine anisotropic effects to enhance the precision of crankshaft design.Metallographic and fractographic analyses offered significant practical insights for the design and optimisation of forged steel crankshafts. Additionally, finite element analysis can indicate the influence of stress on the mechanical part by correlating microstructural features and failure mechanisms, providing insights that can effectively guide the limiting crankshaft performance to extend service life.The study provides unique insights into how microstructural and stress variations influence the crankshaft’s ability to endure operational stresses. The values underscore the critical role of FEA utilisation and advanced quality control strategies in enhancing the reliability, efficiency, and precision of future crankshaft development, ultimately contributing to improved performance and durability in automotive applications.
To investigate the influence of the water factor, filtration resistance coefficients of the bottomhole formation zone, and the diameter of tubing on the wellhead pressure and duration of the natural flow period of a watered gas well and to substantiate technical and economic measures to improve the efficiency of its operation using the reservoir gas own energy.The paper employs mathematical modelling to analyse the influence of determining factors on the natural flow mode of gas wells. Calculations were performed using analytical dependencies. A series of studies was conducted to determine the optimal combinations of water factor, tubing diameter, and filtration resistance coefficients of the bottomhole formation zone for different values, ensuring efficient well operation under waterflooding conditions.Based on the results of the conducted studies, it was found that the wellhead pressure and the duration of the period of natural flowing of a watered gas well increase with an increase in the degree of reduction of the coefficients of filtration resistances of the bottomhole formation zone and decrease with an increase in the diameter of the tubing and the water factor. Based on the modelling, it was determined that the optimal value of the degree of reduction of the coefficients of filtration resistances A and B is 4.271, which provides the best balance between hydraulic pressure losses and well operation efficiency under conditions of partial watering.The studies were performed for different values of the water factor, tubing diameter, and the degree of reduction of the filtration resistance coefficients A and B. To establish the period of flowback operation of a watered gas well, additional modelling studies are required for specific fields and operating conditions.The obtained research results will enable the enhancement of the efficiency of gas well fountain operations under watering conditions.According to the results of the statistical analysis of the calculated data, the optimal value of the degree of reduction of the coefficients of filtration resistances of the bottomhole formation zone of a watered gas well was determined, which is 4.271 for all studied values of the tubing diameter.
The study investigates the influence of niobium (Nb) doping on the low-temperature refrigeration capacity of the magnetoelectric (ME) material Co₄Ta₂O₉ (CTO). The primary aim is to explore the potential enhancements in magnetoelectric coupling and electrocaloric properties due to Nb substitution, using a phenomenological model to predict the magnetic-field-induced electrocaloric effect (MECE).A phenomenological model, rooted in Curie-Weiss-type domain theory, is employed to simulate the temperature dependence of electric polarisation and evaluate the MECE of Nb-doped CTO. Theoretical simulations are corroborated with experimental data, and critical parameters such as entropy change (∆S), maximum entropy change (∆Smax), heat capacity change (∆CP), full width at half maximum (δTFWHM), relative cooling power (RCP) and refrigerant capacity (RC) are calculated to assess refrigeration efficiency.The results demonstrate that Nb doping modifies the magnetoelectric properties by altering the structural and electronic configurations of Co₄Ta₂O₉.The work is limited to theoretical simulations supported by prior experimental data. Further experimental validation of the predicted MECE and long-term stability of Nb-doped compounds under operational conditions is recommended for practical adoption. Future work could also explore different dopant concentrations and combinations to achieve optimised performance.The study suggests that low-polarisation magnetoelectric materials can be effective for magnetic refrigeration applications, offering benefits such as reduced hysteresis loss and broader operational temperature range. The results can inform the design of efficient, sustainable, and cost-effective cooling devices that utilise electrocaloric effects.It is the first study to theoretically predict the MECE in Nb-doped CTO using a phenomenological approach. The novelty lies in identifying and quantifying the impact of Nb doping on electrocaloric performance, offering a new perspective on the use of low-polarisation materials in refrigeration applications.
The purpose of the paper is to investigate the mechanical behaviour of bimetallic sheets manufactured using Laser Powder Bed Fusion (L-PBF) technology and subjected to hydraulic bulge testing. The objective is to analyse the influence of layer configurations and material distribution on the deformation response, aiming to optimise the forming conditions of hybrid additive-manufactured structures.A combined analytical and numerical approach, based on the Finite Element Method (FEM), was employed to predict the deformation and stress distribution during the bulge test. Experimental validations were conducted to verify the accuracy of the simulations. Various configurations of CuCr1Zr and AlSi10Mg layers were produced and tested, with constant total sheet thickness, to assess the impact of material stacking on the mechanical response.The results indicate that the material composition and layer distribution significantly impact the mechanical response of the sheets. Sheets with a higher proportion of CuCr1Zr required greater forming pressures compared to AlSi10Mg. Numerical simulations showed good agreement with experimental results, with relative errors below 10%, validating the accuracy of the developed FEM model. Multilayer bimetallic structures demonstrated enhanced mechanical performance and better control of deformation behaviour.The study is limited to specific materials and simple geometries. Future work will explore more complex shapes, other material combinations, and thermal effects during the forming process. Additionally, the investigation of springback, a critical phenomenon after forming, is recommended to improve the geometrical accuracy of the formed parts.The results provide a basis for optimising additive manufacturing and forming parameters for bimetallic sheets in industrial applications, particularly in the automotive and aerospace sectors. The work contributes to the development of lightweight hybrid structures with tailored mechanical properties.The study is among the first to combine analytical, numerical, and experimental approaches to investigate the hydroforming behaviour of 3D-printed bimetallic sheets. It highlights the importance of material configuration in enhancing the mechanical response and opens the way for better control of forming processes and springback in hybrid additive-manufactured structures.
The aim of the study is to measure, model and reduce the acoustic impact of the conveyor belt system planned for one of the Polish power plants. This system is at the design stage and its elements will constitute additional noise sources.The analysis includes assessment of noise sources and making an acoustic model for the current state of the conveyor system, followed by preparation of an acoustic model for the designed system for transport of biomass and calculation of the level of noise emission in the environment from the Power Plant area. The study also includes proposals for the system optimisation dedicated to minimising the acoustic impact.The analyses carried out confirm that the need to minimise the acoustic impact on the environment of belt conveyors operating in power plants directly is of an individual nature and depends on the location of the layout of these conveyors in relation to the land use of adjacent areas and the permissible noise values for them.When designing new installations, it is necessary to take into account not only the selection of the acoustic parameters of the equipment and mitigation measures, but also the possibility of using the existing infrastructure located in the path of noise transmission in shielding.The methodology used, both measurement and optimization one, using the virtual reality simulations, can be applied as a universal tool for limiting the noise emitted into the environment by conveyor belt systems operating in various conditions.
