Technológ - Ročník 17.; Číslo 2/2025
Permanent URI for this collectionhttps://drepo.uniza.sk/handle/hdluniza/1243
Browse
Item Analýza tribologických vlastností kompozitného materiálu PA66+GF25(University of Žilina, 2025) Bronček, Jozef; Drbúl, Mário; Čuchor, Dávid; Madaj, RudolfThe aim of experiments was to acquire the knowledge that can be used in designing materials for bearing cages. The current trend is that leading bearing manufacturers are replacing metal cages in bearing construction with glass fiber (GF) reinforced polyamide (PA) cages. Experimental measurements were realized on the experimental device linear microtribometer working on the principle of method ball on plane. This method according to the standard ISO 7148-2 is standard method for tribological properties testing. The structure analysis of experimental samples was performed because of understanding of potential structure influence on material properties.Item Giga casting ako technologická revolúcia vo výrobe automobilov(University of Žilina, 2025) Bolibruchová, DanaGiga casting is referred to as a technological revolution in automobile manufacturing. Large aluminium castings are increasingly used for the production of automotive vehicles, especially for electric vehicles with low weight and to reduce production costs. Since most of them are structural components loaded quasi-statically, dynamically and cyclically, the quality and quantifiable performance of extremely large aluminium castings is crucial for their production. This article briefly analyses the current state of the art in the field of giga castings, some examples of their use in the automotive industry, their benefits and advantages.Item Analýza stavu povrchu po shot peenovaní duplexnej ocele AlSi 318(University of Žilina, 2025) Neslušan, Miroslav; Florková, ZuzanaThis paper deals with surface integrity and the corresponding stress state as well as surface topography after shot peening of duplex steel AlSi 318 under the variable shot-peening conditions such as number of passes and applied air pressure. It was found that the energy of shot impacts is consumed mainly by austenitic phase whereas the ferritic one is less affected. High magnitude of residual stresses is developed under the higher number of cycles as well as for the higher media pressure. Amplitude of compressive residual stresses in austenite is more as that for ferrite one. Surface roughness is decreasing along with the number of shot peening cycles and the typical crater-like surface is produced.Item Ultrazvuková kontrola zvarov na železných materiáloch s hrúbkou do 8 mm(University of Žilina, 2025) Koňár, RadoslavThe paper deals with the possibilities of inspecting butt welds on steel materials with a wall thickness of up to 8 mm using phased array ultrasonic technology. The possibility of using ultrasonic technology also for materials with a wall thickness of up to 8 mm will allow in practice the extension of ultrasonic inspections to welds that are currently inspected only by the x-ray method. Ultrasonic inspection could fully replace the x-ray test, thereby increasing the efficiency and flexibility of NDT inspections in the construction of steel structures.Item Vplyv geometrie reznej hrany na tvorbu triesky a zložky reznej sily(University of Žilina, 2025) Mičietová, Anna; Čilliková, MáriaThis paper deals with influence of cutting edge geometry on chip formation and components of cutting force components. The insert with the flat surface is compared with the insert containing positive geometry in order to produce acceptable chip form. It was found that cutting forces components are lower for the insert having positive geometry together with the lower energy consumed for chip formation. Furthermore, the acceptable chips in the form of short sequence is developed as contrasted against the insert of flat surface producing long chips. The measured cutting force components are decomposed in order to distinguishes between the components associated with chip formation and energy consumed in the produce new surface. Chip ratio for the flat insert is more and the shearing angle is therefore less.Item Opotrebenie strižníkov a ich ostrenie(University of Žilina, 2025) Moravec, Ján; Melo, BorislavThe paper focuses on the issue of shear wear. Theoretical foundations are presented and an analysis of the issue of sharpening the active parts of the shear tool is also described. Sharpening the shears themselves is an important part of repairing shear tools and their required starting position before setting them on the press.Item Technológ - celé číslo 2/2025(University of Žilina, 2025)Item Numerická štúdia vplyvu teploty jadra na tepelné zaťaženie vysokotlakovej formy pri výrobe odliatkov pre EC motory(University of Žilina, 2025) Matejka, Marek; Podprocká, RadkaThermal loading of the die in high-pressure die casting is a complex phenomenon driven by the interaction of the molten metal with the die surface. This interaction leads to cyclic temperature changes, steep thermal gradients, and thermal shock, all of which significantly impact the integrity of the die. During each injection cycle, dramatic temperature changes occur on the die surface. Molten aluminum comes into contact with the die surface, which can reach peak temperatures exceeding 450°C, causing high temperature fluctuations. The aim of the experiment was to investigate the influence of two different thermoregulation media - water and ITERM 6MB heat transfer oil - on the thermal behavior of the die cores for EC 75 and EC 55 castings. Experimental results showed that water cooling leads to more efficient heat dissipation and lower temperatures in the core, while oil tempering ensures higher and more stable temperatures. Analysis of the temperature distribution in the die closing and opening phases confirmed that while water cooling leads to more intensive cooling, oil tempering contributes to a more uniform thermal regime and a potential reduction in thermal shock, which is crucial for die life and casting quality. Significant differences were observed in the cores' thermal behavior for EC 75 and EC 55 castings, despite their differing tubular section heights.Item Analýza a výber batériových systémov pre nezávislú elektrickú trakciu v železničnej doprave(University of Žilina, 2025) Samaš, Vladimír; Bučko, Martin; Adamkovič, MatúšThe increasing emphasis on environmental sustainability in rail transport is leading to a search for alternatives to conventional diesel rolling stock, especially on non-electrified or partially non-electrified local lines. Battery traction electric systems represent one of the prospective options, with their efficiency largely dependent on the choice of appropriate battery technology. Range optimization in this context means achieving the maximum possible distance a vehicle can travel on a single charge, considering weight, power and operating conditions, which tend to be variable during operation. An important aspect is also the analysis of the production and operating costs depending on the lifetime of the different battery types. In this paper, four main types of batteries usable in rail transport are compared - Li-ion (conventional lithium-ion), LiFePO₄ (LFP), Li-Titanate (LTO) and Lithium Polymer (Li-po). They are compared in terms of technical parameters (energy density, voltage, cycling life), cost effectiveness, safety and suitability for railway applications. The analysis also includes an assessment of the potential of sodium-ion (Na-ion) batteries as a future alternative.Item Kinematická analýza rovinného paralelného mechanizmu s tromi vodiacimi reťazcami s neidentickou štruktúrou(University of Žilina, 2025) Michalková, Mária; Guldan, Vladimír; Ftorek, BranislavIn this paper, we analyse the mobility of a planar parallel mechanism with three serial chains. The serial chains consist of three joints with one degree of freedom (rotational and translational), but with a different arrangement or combination of the mentioned joints. Using the Screw theory concept, there is investigated the mobility of the end effector, and the direct and inverse problem for the speeds is formulated, as well. Further, we deal with the occurrence of singular positions of such a mechanism.Item Kvantitatívne hodnotenie náchylnosti Al-Si-Cu-Mg zliatiny s prídavkom titánu na vznik trhlín za tepla(University of Žilina, 2025) Sýkorová, MartinaThis study presents a quantitative evaluation of the effect of titanium (Ti) additions on the hot-tearing susceptibility of the AlSi5Cu2Mg aluminium alloy. The AlSi5Cu2Mg aluminium alloy is used in the production of highly stressed cylinder head castings and is characterized by an increased susceptibility to hot tears. The main objective of the study was to determine the extent to which grain refinement of the aluminium alloy with an excessive amount of Ti affects its susceptibility to hot tears. Thermal analysis was performed to characterize the solidification behaviour of the experimental alloys. Grain refinement was evaluated metallographically by measuring the Dendrite Arm Spacing (DAS) index. The results confirmed that the addition of titanium led to a decrease in the hot tearing susceptibility of the AlSi5Cu2Mg alloy.Item Analysis of the effective use of work tools(University of Žilina, 2025) Biňasová, Vladimíra; Mičieta, Branislav; Buzalka, Martin; Kasajová, MartaThis article deals with the analysis of the effective use of work tools in different work environments. The aim of the study is to identify the key factors influencing the use of tools and to propose recommendations for optimizing their use to increase productivity and safety. The analysis is based on worker experiences, observations and quantitative data, which reveal the importance of proper selection, maintenance and training in the use of work tools. The results indicate that the effective use of tools has a significant impact on work performance, reducing risks.Item Overcasting ako inovatívna metóda spájania kovových materiálov(University of Žilina, 2025) Medňanský, Martin; Brůna, MarekThis article focuses on the research of innovative metal casting technology of overcasting (or compound casting) as a progressive method of joining metal materials in different phase states (solid-liquid). Overcasting allows the creation of bimetallic components with a diffusion-bonded interface that combine the advantageous properties of the matrix and core. It can offer high efficiency, greater design flexibility and weight savings, if suitable materials are joined. The article reviews different approaches to joining similar and dissimilar materials.Item Spracovanie technických materiálov z matematického hľadiska(University of Žilina, 2025) Malacká, ZuzanaThe processing of technical materials is a key process in many industries, such as mechanical engineering, automotive, aerospace and energy. Mathematical modelling of these processes allows for a better understanding and optimization of processing techniques, which leads to increased efficiency and product quality. This article focuses on the application of mathematical methods in the processing of technical materials, including the analysis of mechanical properties, thermal behaviour and material flow dynamics. Examples from the fields of forming, welding and casting are presented, demonstrating the importance of mathematical approaches in improving the quality and efficiency of production.Item Progress in advanced industrial engineering(University of Žilina, 2025) Biňasová, Vladimíra; Mičieta, Branislav; Kasajová, Marta; Zuzík, JánIndustrial engineering continuously evolves to meet the demands of modern manufacturing and service systems. With the integration of new technologies and innovative methodologies, advanced industrial engineering plays a crucial role in optimizing processes, increasing efficiency, and reducing costs. This article explores recent developments, key trends, and future prospects within this dynamic field.Item Ručné obrábanie kovov pilovaním(University of Žilina, 2025) Moravec, JánThe presented contribution focuses on the field of manual metal processing using filing technology. Knowledge about the production of files, the geometry of file teeth are presented. Some selected findings from the subject area are presented.Item Study of local mechanical properties and deformation mechanisms of the soft zone of welded joints of high-strength steels(University of Žilina, 2025) Harvanec, Jakub; Mičian, Miloš; Frátrik, MartinHigh-strength steels (HSS) are crucial in the production of lightweight structures. Their welding creates a distinct heterogeneous heat-affected zone (HAZ) in which a softened zone with locally lower mechanical properties forms. This critical zone acts as a weak point, concentrates strain, and can initiate failure, thereby compromising the structural integrity of the welded joint. Detailed understanding of the local behaviour of this zone is insufficiently investigated. Standard tests provide only basic data, which limits the reliability of simulations and the integrity assessment of steel structures. The article deals with the characterization of the local mechanical properties and deformation behaviour of the HAZ softened zone using the DIC (Digital Image Correlation) and nanoindentation techniques. The combined approach enables a comprehensive understanding of the mechanical properties of the HAZ subzones, crucial for assessing the reliability and integrity of welded structures.Item Vplyv precipitačného vytvrdzovania na mechanické vlastnosti nehrdzavejúcich ocelí(University of Žilina, 2025) Kantoríková, ElenaThe article aims to highlight the impact of heat treatment - precipitation hardening on stainless steels. Precipitation hardening allows to achieve very high mechanical properties (tensile strength and yield strength), often significantly higher than in classical austenitic or ferritic steels. The aim is to compare the theoretical conditions of heat treatment and thus increase awareness of its advantages.Item Tvárnenie plechu veľkou uvoľnenou energiou(University of Žilina, 2025) Moravec, Ján; Melo, BorislavThe paper analyzes an unconventional method of forming sheet metal parts with high energy release. Published diagrams and images together with a physical description of the process illustrate how this technology can be applied to form large-sized sheet metal parts at low production costs. The text presents important mathematical equations that are part of the physical description together with technological parameters. A brief economic evaluation is presented in the conclusion.