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Analysis of Extrusion Process Parameters in PLA Filament Production for FFF TechnologyVojtech Senkerik, Martin Bednarik, Vaclav Janostik, Michaela Karhankova, Ales MizeraManufacturing Technology 2024, 24(2):265-271 Additive technologies are becoming a common part of not only prototype production, but also piece or small series production. However, the choice of technology and material plays a key role in the applicability of the manufactured parts. The most widespread type of additive technology is FFF technology, which consists of applying a fused plastic string in single layers. The resulting mechanical properties of parts produced using this technology depend not only on the material and structure selected, but also on the process parameters used in the printing process itself. This study deals with the production of filament from PLA, which is the primary material. The advantage is its environmental degradability after the end of the life cycle of PLA products. However, the resulting properties of the printed parts may depend on the way the filament is prepared and in particular on the melt temperature during filament extrusion. This study investigates the effect of the produced filaments on the quality of printed parts. It has been shown that the filament production technology has a significant effect on the quality of printed parts. |
Numerical and Experimental Study into forming of the longitudinal Externally Spline Sleeves by internally rotary Ballizing ProcessAyman Ali Abd-Eltwab, Emad A. Fahmy, Mohamed N. El-Sheikh, Ahmed M.I. Abu-Oqail, Hammad T. Elmetwally, Eman S. M. Abd-ElhalimManufacturing Technology 2025, 25(6):758-770 | DOI: 10.21062/mft.2025.076 longitudinal externally splined parts have garnered increasing attention due to their critical role in power transmission across various industrial applications. This study explores the use of the internally rotating ballizing technique for manufacturing these components. The process was analyzed both experimentally and numerically through a mathematical model. The experimental investigation focused on key process parameters, including die rotational speed (50, 63, 80, 100, 125, 160, 200, 250, and 315 rpm), axial feed rate (0.13, 0.15, 0.18, and 0.21 mm/rev), interference between the balls and the tubular sample (cross in-feed: 2.5, 3.5, 4.5 and 5.5 mm), and initial tube thickness (4, 5, 6 and 7 mm). The study assessed the influence of these variables on the forming load and the quality of the produced longitudinal externally splined sleeves. A numerical model was developed to predict forming loads, and the findings indicated that these parameters significantly affect both (forming load and filling ratio). The optimal values for these variables were identified, and the numerical results showed a strong correlation with experimental findings. Keywords: Externally Splined Sleeves, rotary Ballizing Process, Numerical method, Experimental Study and forming load. |
Experimental Measurement and Testing of 3D Printed Parts in Terms of the Material UsedAlexandr Fales, Vít Černohlávek, Marcin Suszynski, Jan Štěrba, Tomáš Zdráhal, David NocarManufacturing Technology 2025, 25(2):174-184 | DOI: 10.21062/mft.2025.016 As part of my research work, in its practical part, I deal with the selection of suitable 3D printing pa-rameters for parts of a robotic kit, as well as the selection of a 3D printer and the determination of a set of experimental measurements and testing in order to obtain the necessary data to determine a suitable filament material for 3D printing of a part of a robotic kit and setting the appropriate 3D printing parameters to obtain the desired mechanical properties of the parts while maintaining the economic benefits of 3D printing. The main aspects for choosing a filament material are printability in primary and secondary school conditions, easy printing (beginner level), minimal postprocessing, adequate mechanical properties – these are obtained by experimental measurement and correspon-ding destructive tests on a real part from the VEX GO and IQ kit. |
Thermal Analysis of Micro Plasma Wire Arc Additive Manufacturing Deposition ProcessSiti Khairiyah Sulaiman, Mohd Rizal Alkahari, Mohd Juzaila Abd Latif, Yupiter Harangan Prasada Manurung, Keval Priapratama PrajadhianaManufacturing Technology 2025, 25(3):396-404 | DOI: 10.21062/mft.2025.039 Additive manufacturing (AM) is rapidly developing with emerging technology of wire arc additive manufacturing (WAAM) process due to its ability to manufacture large components and high deposition rate. However, WAAM faces mechanical properties problems like porosity, distortion, and strength due to the large heat affected zone (HAZ) from commonly used heat sources such as metal inert gas (MIG) and tungsten inert gas (TIG). Utilization of micro plasma as the heat source should reduce this problem since it has a smaller heat source diameter. Therefore, this study investigates the thermal distribution of micro plasma wire arc additive manufacturing (MPWAAM) by developing a finite element method (FEM) model. This paper focuses on the fabrication of single-layer multitrack deposition and tool path planning of multi-layer multitrack depositions by MPWAAM process. The melt pool size and peak temperature are mainly governed by heat input per unit travel speed of the worktable, with current and voltage being the significant factors. Besides, tool path planning strategy influences the properties and quality of the final product, where parallel tool path design with longer interlayer cooling time minimized part distortion and residual stresses. |
Mechanical Alloying, an Innovative Way of Zinc Preparation for Biomaterial PreparationDavid Nečas, Jan Blažek, Jan Pokorný, Anna Boukalová, Jiří KubásekManufacturing Technology 2025, 25(5):662-669 | DOI: 10.21062/mft.2025.070 In this study, binary zinc-based alloys (Zn–1Mg, Zn–1Li, Zn–2Mn, wt.%) were synthesized by performing mechanical alloying (MA) of elemental powders, followed by consolidation using spark plasma sintering (SPS). The processing parameters were optimized to obtain homogeneous powders with controlled particle size. X-ray diffraction and SEM analyses confirmed the presence of secondary intermetallic phases (Mg2Zn11, Zn13Mn, ZnLi2 phases) formed during milling, which were preserved after SPS. Microstructural examination revealed a fine-grained microstructure with residual oxide networks originating from powder surfaces. Mechanical testing demonstrated significant strengthening effects after Mg and Li additions, with Zn–1Mg alloy reaching the highest hardness (128 HV1) and compressive strength (526.7 MPa), attributed to uniformly distributed Mg2Zn11 precipitates. However, this strengthening was accompanied by reduced ductility. Zn–1Li exhibited the most balanced combination of strength and plasticity, while Zn–2Mn provided only a limited improvement over pure zinc. These results confirm that mechanical alloying combined with SPS is a promising route for developing biodegradable Zn-based biomaterials with enhanced properties. |
Studies on a Robotised Process for Forging Steel Synchronizer Rings in the Context of Forging Tool LifeArtur Meller, Marcin Suszyński, Stanisław Legutko, Marek Trączyński, Vit CernohlavekManufacturing Technology 2023, 23(1):88-98 | DOI: 10.21062/mft.2023.002 This paper proposes a solution not previously used in the forging industry, which aims to reduce the proportion of arduous human labour. The concept of a prototype robotic station for hot forging includes a system that allows the selection of batch material with its heating, the execution of the process of lu-brication of forging tools and the forging itself, synchronised with the feeding and removal of material using full automation, in accordance with the idea of Industry 4.0. At the same time, by increasing the repeatability of the entire forging process and changing some of its key parameters, it will be possible to influence the durability of the tools used during its implementation. In order to verify the impact of such a modified technological process on forging tool life, computer simulations of forging were performed, where the currently applied technology using hand forging was compared with a conceptual automated process. |
Microstructural Analysis, Corrosion Resistance, and Wear Performance Study of Al0.8FeCoNiCrCu0.5Si0.2 High-Entropy AlloyPeng Zhang, Yanzhou LiManufacturing Technology 2024, 24(4):700-709 | DOI: 10.21062/mft.2024.062 The high-entropy alloy with the composition Al0.8FeCoNiCrCu0.5Si0.2 was produced through a pro-cess in-volving a vacuum arc melting method. Comprehensive characterization was performed through techniques such as XRD, SEM, and TEM. The findings revealed that the alloy primarily con-sists of Fe-Cr and Al-Ni phases, displaying predominantly two body-centered cubic structures. The alloy exhibited a characteristic dendritic cast structure. The alloy predominantly has high-angle grain boundaries accounting for 96.1%. Its grains demonstrate minimal internal strain and reduced lattice anomalies. The alloy showcased resistance with a corrosion current density of 1.4×10-7 A/cm2 and a corrosion potential of 0.28047 V. Post-corrosion examinations emphasized regions abundant in Al and Cu as the primary degradation sites. The addition of Si has further improved the alloy's resistance to corrosion. In terms of abrasion durability, the alloy exhibit-ed a wear scar length of only 1.42 mm, substantially less than the 1.88 mm found in 45# steel, highlighting its enhanced resistance to wear. This wear resistance is attributed to its inherent BCC1 and BCC2 phase structures and the hardness it derives from its unique composition. Owing to its superior traits, this high-entropy alloy presents promising potential for applications, including coatings, and advanced automotive components. |
Determining the Force Required to Remove a Screw from a Human VertebraPatrik Balcar, Petr Vachata, Martin Svoboda, Jan Lodin, Michal Lattner, Antonín Svoboda, Edita PichlováManufacturing Technology 2025, 25(6):721-727 | DOI: 10.21062/mft.2025.080 The article describes a pilot experiment of mechanical testing of 3D printed vertebrae with an inserted screw. The main goal of this work was to verify the design of a measurement methodology for experimentally determining the mechanical properties of vertebrae produced using 3D printing and also for determining the load-bearing capacity of a screw when it is drilled into a vertebra. The work describes the construction of a special fixture with which it is possible to clamp test samples for tensile testing. The stud screws were pulled out of a real or printed vertebra using a tearing machine. Testing was performed on porcine and 3D printed vertebrae. CT images of porcine spines obtained by a computed tomography scanner were used to create the printed vertebrae. This work verified the mechanical properties of printed and real vertebrae. In connection with this work, suitable printed materials and the necessary parameters of 3D printed samples will be sought so that they correspond to the necessary mechanical properties and can replace human vertebrae. It will then be possible to conduct laboratory investigations to obtain better results in spinal stabilization. The experiments verified the measurement methodology, compared the measured values between real and printed vertebrae, and also determined the next direction of research. |
Investigation of the Wear Progression of Nozzle in Abrasive Waterjet Machining with Different Abrasive MaterialNuraini Lusi, Mebrahitom Gebremariam, Abdur-Rasheed Alao, Kushendarsyah Saptaji, Azmir AzhariManufacturing Technology 2025, 25(1):76-85 | DOI: 10.21062/mft.2025.011 Determining the productivity and quality of precision AWJ machining requires routine and careful inspection of nozzle condition. The degradation of the inner bore of the nozzle adversely impacts the mixing efficiency and uniformity of the water jet, thereby affecting its cutting performance. In this study, new nozzle was designed and manufactured using additive manufacturing and were made of 316 L stainless steel. The new nozzle consists of two combined parts with the peculiarity of being easy to install using a screw thread. The wear behavior of the new nozzle was examined using an accelerat-ed wear test. An accelerated wear test was conducted on the hard abrasive silicon carbide (SiC) and compared to garnet, the abrasive commonly used in the AWJ industry. The aim of the test was to de-termine the wear pattern of the nozzle. The cumulative mass loss and nozzle diameter increase for different abrasives were measured. The geometric change in the nozzle is made visible through de-structive examination. The findings indicated that the type of abrasives significantly affects nozzle wear. As the hardness of the abrasive increases, the diameter of the nozzle enlarges, resulting in accel-erated nozzle wear. The mass loss factor of SiC abrasives is three times higher than that of garnet abrasives. This research allows practitioners to monitor the nozzle wear behaviour during the AWJ process. The results obtained were used to estimate the nozzle life based on the observed wear history. |
Milling Performance of Selective Laser Melted Ti6Al4V: A Taguchi Approach for Surface Roughness OptimizationIkhsan Siregar, Juri Saedon, Mohd Shahriman AdenanManufacturing Technology 2025, 25(2):230-238 | DOI: 10.21062/mft.2025.030 Titanium alloy Ti6Al4V fabricated using Selective Laser Melting (SLM) has gained significant attention in biomedical and aerospace applications due to its superior mechanical properties and design flexibility. However, its machining characteristics, particularly in milling, remain challenging due to the material's hardness and thermal conductivity. This study investigates the milling performance of SLM-manufactured Ti6Al4V by optimizing surface roughness using the Taguchi method. An L9 orthogonal array was employed, considering spindle speed, feed rate, and depth of cut as control factors. Surface roughness measurements were analyzed using Signal-to-Noise (S/N) ratios, and Analysis of Variance (ANOVA). Results indicate that spindle speed significantly affects surface roughness, contributing over 83.67% of the total variation. The optimized milling parameters resulted in a notable improvement in surface quality, highlighting the effectiveness of the Taguchi method in achieving better machinability for additively manufactured titanium alloys. This study offers useful insights to improve the milling process of SLM-made Ti6Al4V, helping boost performance in industrial use. |
Evaluation of the Degradation of Combustion Engine ValvesPavel Novak, Jan Růžička, Ester DuchkováManufacturing Technology 2024, 24(5):811-816 | DOI: 10.21062/mft.2024.084 This work aims at the description of the degradation of the intake and exhaust valve of the combus-tion engine during operation. For the experiments, new valves from Ford Fiesta were used, as well as the used ones with known mileage. In order to simulate the valve long-term operation and to esti-mate the temperature of the valve during the use, the new valves were annealed at 700 – 900 °C for 1000 h (corresponding to the mileage of 70,000 km with average speed of 70 km/h) and the grain size was compared with the used valves. It was found that this model experiment can easily predict the operation temperatures of the exhaust valves, which were made of the heat-resistant austenitic steel. However, the metallography procedure for the determination of the grain size fails in the case of the martensitic steel valves. |
Measurement of Heat Transfer in a Sand Mould Foundry – Optimisation of Cooling Time for Cast Iron And Ductile Cast Iron Mass CastingsJan BredlManufacturing Technology 2025, 25(2):161-169 | DOI: 10.21062/mft.2025.024 Cast iron with nodular graphite is one of the most important structural materials that exhibit really good mechanical properties already in the as-cast condition. Nowadays, cast iron with nodular graphite is used in many areas of the manufacturing industry, the most widespread being in the engineering and automotive industries. The applicability of this material for construction purposes is mainly due to its mechanical properties, which are close to those of steel, but the production cost of cast iron is lower. This experiment was aimed at optimizing the production of ductile iron castings in the casting pits so that the foundry could produce ductile iron castings in the casting pits. Therefore, the optimization of the moulding compound database material was carried out in numerical simulation and at the same time, the heat transfer measurement of the foundry sand mould was carried out. |
Observation of the Amount of Wear and the Microstructure of Hardfacing Layers after the Test of Resistance to Abrasive WearMiroslava Ťavodová, Miroslav Džupon, Monika Vargová, Dana Stančeková, Jozef KrilekManufacturing Technology 2024, 24(1):131-140 | DOI: 10.21062/mft.2024.003 The article deals with the evaluation of the amount of wear of the base material and selected hardfac-ing materials intended for tools for wood processing in forestry after a test of resistance to abrasive wear in laboratory conditions. The values of average weight loss Wh[g] and relative resistance to abrasive wear Ψh[-] were determined by calculation. The topography of the surface after the track of the rubber disc and the abrasive of the testing device was evaluated with a confocal microscope. The depth of the disc track Pt[μm;mm] was also evaluated with a confocal microscope. The state of the samples surface after the test, as well as the overall structure and mixing of the hardwearing material with the base material was evaluated by light microscopy. A touch roughness meter was used to de-termine the profile of the track surface after the test. Based on the results, we can recommend certain hardfacing materials for practice. Their abrasive resistance and thus also the loss of material during the work load could ensure a longer service life of the tool. |
Microtexturing for Enhanced Machining: Evaluating Tool Performance in Laser-Processed Cutting InsertsOndrej Bilek, Jan Ondrik, Petr Janik, Tomas KautskyManufacturing Technology 2024, 24(2):173-182 This article explores the significance of microtexturing on cutting tools for improved tribological performance and reduced friction in machining operations. Drawing inspiration from biomimetic structures, the study focuses on laser surface microtexturing and evaluates its impact on cutting forces and tool wear. Experiments involve microtextures of dots with a specific emphasis on a fiber laser-processed pattern. While long-term tests reveal the formation of negative protrusions on the textured tools, reduced variability in cutting forces suggests potential benefits for stable machining processes and increased tool longevity. The findings underscore the intricate relationship between microtexturing patterns and tool performance, offering insights into the broader implications for energy-efficient machining. |
The Effect of a Mixture of Methanol and Gasoline on the Operation of an Engine in an Electric Power Generator SystemJaroslav Mrázek, Martin Pexa, Jakub ČedíkManufacturing Technology 2024, 24(4):636-644 | DOI: 10.21062/mft.2024.070 Methanol, a type of alcohol, with gasoline, a conventional fossil fuel used in internal combustion engines. This blending process is often done to create an alternative fuel that may have certain advantages over using gasoline alone. The combination of methanol and gasoline can offer benefits such as improved combustion efficiency, reduced emissions, and potentially lower overall fuel costs. Methanol has a high-octane rating, which can enhance the combustion characteristics of the fuel mixture. This can lead to more efficient and cleaner combustion in internal combustion engines. Conducting this research is essential to explore potential improvements in fuel efficiency, emission reduction, and overall system performance, which are critical for advancing sustainable energy solutions. The tests were done using a mobile generator Briggs and Stratton ProMax 3500A. The tested fuels were 10 %, 20 % and 50 % blends of methanol in gasoline. The electrical output of the generator was roughly the same for all fuels even at higher load, however consumption increased significantly. The mixtures had a negative effect on the stability of engine operation and engine emissions had a negative effect at most of the measurement points. In some cases, like the concentration of formaldehyde by weight, gasoline fuel mixtures showed a decrease in mass concentration at lower engine loads and an increase at higher loads compared to the reference fuel. |
Demonstration of Neural Network in Prediction of Bearing LifetimeEliška CézováManufacturing Technology 2025, 25(2):170-173 | DOI: 10.21062/mft.2025.017 The topic of this paper is the application of machine learning and neural networks in engineering, specifically in the prediction of the lifetime of bearings operating in different conditions. In addition, the basics of machine learning are introduced, giving an idea of the importance of input data quality for model training. It also presents the elements of neural network training to be used in other projects. The article is supplemented by a source code examples written using only the Python language, and some other popular libraries, like the NumPy, Matplotlib, Tensorflow, Keras, and Scikit-learn. The main advantage of the libraries used is that they are freely available and widely used, bringing variety of sophisticated tools for gen-eral use. |
Experimental Measurement of Defects Propagation for a Passenger Car Tire Casing under Dynamic LoadingJán Vavro jr., Ján Vavro, Lukáš Klimek, Miloš Taraba, Tomasz Domański, Zbigniew Saternus, Petra DubcováManufacturing Technology 2025, 25(5):698-710 | DOI: 10.21062/mft.2025.071 The given paper deals with the defects propagation in car tires for passenger vehicles under dynamic loading. The occurrence of defects has the significant influence on the lifetime and quality of the tire, especially during its operation as a part of the vehicle. The given defects are closely connected with a safety in road traffic. The aim of the study was to carry out a non-destructive analysis of the car tire for the purpose to analyze the defects propagation as well as to introduce the defects classification and their location along with the whole course of rupture as a result of increasing speed, loading and the number of hours or kilometers driven. During the analysis, we used a non-destructive method for detecting defects using a non-destructive analyzer that works on the principle of shearography. The experimental measurement was carried out for 12 car tires. The measurement results are displayed from the non-destructive analyzer in the form of protocols from measurement and video display. The evaluation of the results of the measurement for the propagation of defects is displayed graphically. In relation to the tire casing, the analysis of the defects propagation can help design engineers to solve critical issues by choosing the right material, modifying dimensions of individual components or even by redesigning the overall construction of the tire casing and thus to increase the safety from the as-pect of vehicle operation. |
Implementation of Mechanization into the Welding ProcessMiloš Taraba, Ján Vavro, jr., Jan VavroManufacturing Technology 2025, 25(1):120-130 | DOI: 10.21062/mft.2025.001 The article is focused on the investigation of the impact of the implementation of mechanization into the welding workplace, for the production of cylinders from austenitic X5CrNi18 10 chromium nickel steel. The welds are assembled into a production line for the processing of puff pastry. In addition to the technical improvement of the process and the verification of the sufficient quality of the welds, calculations were used to prove that after the implementation of the change, there was a significant reduction in the production time. By introducing a higher level of mechanization and necessary technological changes, the production time was reduced by up to half, compared with the original technological procedure, including an increase in quality parameters and it led to a reduction in the production costs of the welding workplace. A significant consequence of the proposed change was connected with its impact on workplace safety. |
Effect of DCSBD Plasma Treatment on the Mechanical Properties of Polymer FilmsMarcel Kohutiar, Michal Krbata, Róbert Janík, Jozef Jaroslav Fekiač, Lucia Kakošová, Jana EscherováManufacturing Technology 2025, 25(1):37-44 | DOI: 10.21062/mft.2025.012 Polymers and their surface modifications are the subject of intensive research due to their wide industrial applications in the fields of food packaging, biomedicine and electronics. The most widely used polymer films include polyethylene (PE), polyethylene terephthalate (PET) and polypropylene (PP), whose surface and mechanical properties can be optimized through physicochemical modifications. Diffuse coplanar surface barrier discharge (DCSBD) represents an effective method for modifying the surface properties of polymers without significantly affecting their structural properties. This study focuses on analyzing the effect of DCSBD plasma discharge on the mechanical behavior of PE, PET and PP films by means of dynamic mechanical analysis (DMA). Experimental samples were exposed to DCSBD plasma discharge and subsequently subjected to DMA over a wide temperature range. The measurement results showed significant changes in the storage modulus (E′), loss modulus (E′′) and loss angle (tan δ), while a decrease in material stiffness and a shift in glass transition temperatures (Tg) were identified. |
Strain Field Determination for Additively Manufactured Thermoplastics Using Computer VisionJaroslav Majko, Ondrej Piroh, Ján Minárik, Milan Vaško, Marián Handrik, Milan Sága, Zbigniew SaternusManufacturing Technology 2025, 25(4):511-520 | DOI: 10.21062/mft.2025.060 The effective application of additively manufactured materials requires accurate identification of their mechanical properties as well as damage mechanisms. Computer vision offers a novel approach for non-contact measurements, enabling the identification of selected mechanical properties. This paper presents a new method based on image analysis and the detection of circular markers for non-contact displacement measurements. The core principle involves detecting the centers of gravity of the circular markers formed on the sample under investigation. The centers of gravity are evaluated on each image created during the tensile test, representing nodal points. At these points, displacements are determined based on the non-contact extensometer. The deformations sought are a function of the displacements at each nodal point. These values were calculated based on several theoretical models, also used in the finite element analysis. The paper describes the computational procedure for determining the deformations based on the mentioned theoretical models. Subsequently, the total strain field is determined using linear interpolation of the displacement values at the individual nodal points. The results provided by each of the theoretical models were compared. |
Possibilities of Evaluating the Quality of Products Produced by Directed Energy Deposition TechnologyPetr Beneš, David Bricín, Denisa JanováManufacturing Technology 2025, 25(2):153-160 | DOI: 10.21062/mft.2025.025 It is well known that the porosity of a product can have a negative effect on the mechanical properties of the product. For this reason, its control is very important. Porosity can be assessed by two methods - destructive and nondestructive inspection. However, the identification of very small pores is still very difficult for metallic materials, as the pore size may be below the resolution of most commonly used NDT techniques. In addition, different types of pores may be present in a single part, with one type usually dominating. Proper identification of porosity is essential to estimate the impact on structural properties. For pore assessment, as for other defects, the description of the morphology, distribution and frequency is important. This article deals with the comparison of methods designed to determine the porosity of products that have been manufactured using Laser Directed Energy Deposition – L-DED additive process. The samples were made from AISI 316L stainless steel. The porosity of these samples was assessed using destructive and nondestructive methods. Subsequently, their comparison was made in relation to the detection of different pore sizes. The samples were subsequently subjected to the HIP process (Hot Isostatic Pressing). For these samples, the changes that occurred in the material as a result of this process were subsequently quantified. This process should have a positive effect on improving the quality of the product produced by AM technologies, e.g. by reducing the number and size of pores. |
Research on Stator Thermal Fault Detection of Steam Turbine Generator Based on Improved Transformer and Gaussian Mixture ModelFengqin Cheng, Weinan ZhengManufacturing Technology 2025, 25(4):448-454 | DOI: 10.21062/mft.2025.051 This study proposes a multi-stage intelligent diagnostic approach integrating Physics-Guided Normalization (LPGN), enhanced Transformer networks, and Gaussian Mixture Models (GMM) for thermal fault detection in turbine generator stators. The methodology sequentially performs the following steps: (1) enhances localized anomaly features in temperature data through LPGN, (2) efficiently extracts temporal patterns via the optimized Transformer architecture, and (3) achieves unsupervised fault classification using GMM. Experimental results demonstrate the proposed method's superiority over conventional ARIMA and LSTM models across multiple evaluation metrics, exhibiting a lower RMSE and a higher detection accuracy. Ablation studies further validate the individual contributions of each component to performance improvement. This solution provides an efficient and reliable framework for intelligent thermal monitoring in large rotating electrical machinery. |
Ultimate Response of Strengthened RC Beams in the Flexural Using Plain Cementitious Composites LayerAshraf M. Heniegal, Hamdy M. Afefy, Ahmed T. Baraghith, Mostafa Eldwiny, Omar Mohamed Omar IbrahimManufacturing Technology 2024, 24(4):567-577 | DOI: 10.21062/mft.2024.071 This paper aims to study the efficiency of using prefabricated layers made from plain cementitious composite materials for enhancing the flexural behavior of reinforced concrete (RC) continuous beams. The strengthening system was applied at 20 mm thickness, 150 mm width, and adequate development length. The prefabricated layers were placed in the tension cover in the positive and negative zones. All beams have the same geometric dimensions and positive and negative steel reinforcement ratios. The results showed that the prefabricated layer was deformed with the RC specimen without debonding, which enhanced the cracking patterns and distributed the crack width. A slight improvement in the strengthened beam capacity was 7% for the yielding load and 6% for the ultimate load. The energy absorption capacity of the strengthened beam decreased by 30.67%, whereas both beams achieved the same ductility index. |
Dynamic Mechanical Analysis of PLA Produced by FFF Additive Manufacturing Technology after DCSBD Plasma TreatmentMarcel Kohutiar, Róbert Janík, Michal Krbata, Jozef Jaroslav Fekiač, Lucia Kakošová, Pavol MikušManufacturing Technology 2025, 25(2):202-208 | DOI: 10.21062/mft.2025.019 Dynamic mechanical analysis (DMA) is an important method for evaluating the viscoelastic properties of polymeric materials, especially when investigating their mechanical response to various manufacturing parameters and surface treatments. In recent years, DMA analysis has been intensively used, among others, for the analysis of polylactide (PLA) produced by the fused filament fabrication (FFF) additive technology. The present study focuses on the effect of DCSBD plasma treatment on the dynamic-mechanical properties of PLA samples with different infill geometries (Line, Rectilinear and Concentric). In the study, experimental PLA samples were subjected to DMA analysis in the temperature range of 40 °C to 90 °C in order to analyze the changes in their viscoelastic properties after plasma discharge surface treatment. The results showed a decrease in the glass transition temperature (Tg) for all tested samples, while the extent of the decrease depended on the infill geometry used. The most significant changes were observed in samples with Rectilinear infill, which showed the best mechanical stability after plasma treatment. The study shows that plasma treatment can influence the mechanical properties of PLA products, opening new possibilities for optimizing their processing, reuse and application in technical areas requiring controlled mechanical response. |
Surface Treatment of Nylon Filters with Thin Layers of Ti, Cu, and Zr Metals and AgCu Alloys using PVD Magnetron Sputtering TechnologyAnna Krobotová, Totka Bakalova, Michal Krafka, Magdalena Mrózek, Lucie Svobodová, Pavel Kejzlar, Blanka TomkováManufacturing Technology 2025, 25(3):348-356 | DOI: 10.21062/mft.2025.045 The development and characterizing of thin layers of AgCu, Cu, Ti, and Zr on nylon filters using PVD magnetron sputtering technology was conducted. The evaluation of these thin layers was mainly focused on characterizing specific parameters that may influence the expected functionality of the modified filter materials. The surface treatment of nylon filters with thin layers does not significantly affect the mechanical properties of the original nylon material. Thin layers deposited at a power of 0.9 kW exhibited greater thickness and lower static friction coefficient values than the layers deposited at 0.4 kW, except for a thin layer of the element titanium. The surface modification of the filters did not significantly change resistance to deformation and had no significant reduction in pore size. However, a significant effect on surface wettability (increased hydrophobicity) was demonstrated. |
Sinterhardening Process of Lean Cr-Mo Prealloyed Steel for Moderately Loaded ApplicationsDmitriy Koblik, Miroslava Ťavodová, Monika Vargová, Richard Hnilica, Nataša NáprstkováManufacturing Technology 2025, 25(6):771-777 | DOI: 10.21062/mft.2025.082 The article deals with sinterhardening process of lean Cr-Mo prealloyed steel for moderately loaded applications. New material Astaloy CrS with low alloying volume of chromium and molybdenum was analyzed as possible basis for sinterhardening process. Standard mechanical properties of frequently used and more expensive materials such as DistaloyDH and Astaloy CrM are chosen as a compara-tive criterion. Astaloy CrS+0.85%C samples with different compaction densities and Ni content were studied, mechanical properties and hardness after sinterhardening process were compared. The influ-ence of additional high-temperature sintering on mechanical properties was assessed. The micro-structure of the sinterhardening (SH) and high-temperature sintering + sinterhardening (HTS+SH) samples was studied quantitative analysis of the phase was given. As result, tensile strength greater than 900 MPa and hardness greater than 33 HRC can be obtained for investigated material. |
Quality Prediction of Spheroidal Graphite Cast Iron for Machine Tool PartsJan BredlManufacturing Technology 2025, 25(3):287-296 | DOI: 10.21062/mft.2025.032 Today, considerable attention is paid to the production of solid castings (approx. 2000 kg) from cast iron with spheroidal graphite. The metallurgical preparation of large quantities of melt is very difficult. This difficulty is related not only to the melting and preparation of large quantities of melt, but above all to its metallurgical treatment - inoculation and modification. Melt modification ensures the production of cast iron with spheroidal graphite. Material castings, such as machine tool components, cannot be destroyed to determine the quality of the cast iron produced. Therefore, this paper outlines a methodology to proceed in determining the quality of manufactured castings. It is possible to observe the chemical composition of cast iron, thermal analysis of cast iron using liquidus temperature value, subcooling temperature, eutectic recalescence, primary solidification recalescence, eutectic solidification time. Furthermore, to observe the mechanical values of cast iron (yield strength, ultimate strength and ductility) on fabricated bars of overmolded Y blocks or to observe the micro-structure of cast iron on microscope. |
Temperature Matters: Annealing Effects on Silver Protection and Tungsten Oxidation in W@Ag Core-Shell PowderAngelina Strakošová, Pavel Lejček, Ilona Voňavková, Vojtěch DaliborManufacturing Technology 2025, 25(5):689-697 | DOI: 10.21062/mft.2025.063 Core-shell powders have been extensively studied due to their complex structure and wide range of applications. W@Ag core-shell powders are particularly interesting due to the synergy between the tungsten and silver, which can be beneficial in the electronics industry. However, knowledge of their thermal stability is limited, particularly concerning the impact of annealing temperatures on structural integrity and oxidation resistance. In this work, W@Ag core-shell powder was heat-treated in the temperature range 100–700 °C for 1 h in air. Investigation of the microstructural changes using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy showed that the limiting temperature is 500 °C, when the shell began to decompose and the core began to oxidize. Moreover, X-ray diffraction analysis determined that the phase composition of the thus heat-treated material consisted of approxi-mately 50 % Ag and 50 % Ag2WO4. |
Identification of Internal Defects in Forged Shafts by Measurement of Residual Stresses Using X-Ray MethodKamil Anasiewicz, Jerzy Józwik, Michał Leleń, Paweł Pieśko, Stanisław Legutko, Janusz Tomczak, Zbigniew Pater, Tomasz BulzakManufacturing Technology 2024, 24(5):711-720 | DOI: 10.21062/mft.2024.086 The present paper discusses important aspects of residual stress measurements in forged shafts with defects using the X-ray method. A random population of shafts was selected for the study, for which, depending on the type of rolling process, turning was performed, measuring stress changes after successive machining passes. In the forged shafts studied, the existence and location of internal defects were identified using computed tomography. The impact of internal defects on the stress distribution on the surface of the machined workpiece was observed. It was observed that the use of the X-ray method to measure residual stresses makes it possible to determine the state of stresses and their distribution, which is crucial for the safety and durability of shaft-type parts, and allows the impact of a defect on the distribution of residual stresses to be identified. On the basis of the results obtained, it was observed that there is a correlation between the occurrence of internal defects in forged shafts and the distribution of residual stresses in characteristic sections along the length of the shaft after machining |
Creating a 3D Model of a Hovercraft for Research into Structural Shape Optimization and Material Design of Structural PartsMilan Chalupa, Adam Švásta, Zdeněk Krobot, Josef Veverka, Roman Knobloch, Antonín Svoboda, Martin Svoboda, Patrik Balcar, Jaroslav Cais, Jan Štěrba, Michal Lattner, Josef PonikelskýManufacturing Technology 2025, 25(1):2-13 | DOI: 10.21062/mft.2025.007 The article describes the creation of a mathematical 3D model of the original hovercraft structure, which will be further used for research into modifying the shapes and materials of the structure to ensure better driving conditions. Proposals for new materials for individual parts of the hovercraft structure will be addressed in order to reduce the weight of the hovercraft and thereby ensure a higher possible speed of movement, reduce fuel consumption and ensure the necessary mechanical properties of individual segments. The mathematical model of the simplified hovercraft model was created in the Cradle and Adams simulation programs. The paper is presented by analyzing the hovercraft properties in order to obtain sets of advantages and disadvantages of the hovercraft. The following is a description of the creation of a geometric 3D model of the hovercraft, which is built using Autodesk Inventor. The article further describes the transformation of the 3D model into a simulation model that can be used for co-simulation of movement in the Adams and Cradle computer simulation systems. The simulations will be the first step towards modifying the structure of a real rescue UAV prototype with improved maneuverability, stability and the ability to traverse terrain with surfaces unsuitable for hovering. |


