Articles (KTO)

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Showing 1 - 20 out of 35 results

Fatigue behaviour and S-N curve prediction of additively manufactured Inconel 718 using Self-Heating and Energy-Based methods
(2025) Matušů, Martin; Roidl, Bastian; Amann, Simon; Rosenthal, Jakub; Zetková, Ivana; Zetek, Miroslav
Inconel 718, a nickel-based superalloy, is extensively used in high-performance applications such as gas turbines, aerospace, and the nuclear and oil industries due to its exceptional fatigue resistance, corrosion resistance, and mechanical stability across a broad temperature range (−252 °C to over 700 °C). Its weldability and high-strength properties make it suitable for additive manufacturing (AM), particularly laser powder bed fusion (L-PBF). However, the dynamic properties of AM Inconel 718, influenced by surface roughness and microstructural variations, require thorough investigation. This study evaluates the mechanical properties of AM Inconel 718 in two build orientations produced using an EOS M290 printer. Static tests and hardness measurements were conducted to establish baseline properties. The fatigue behaviour was analysed using traditional S-N curve testing alongside a self-heating (S-H) methodology adapted from previous studies on AMed AlSi10Mg. The S-H method, focusing on temperature evolution during cyclic loading, was used to estimate the fatigue limit (FL) and S-N curve predictions. The LinExp method provided slightly conservative FL estimates, which served as lower thresholds for Fargione’s energy-based S-N curve model. Only two specimens per orientation were used, demonstrating its efficiency and resource-saving potential. This work underscores the viability of integrating innovative fatigue analysis techniques with traditional methods to optimize the design and evaluation of additively manufactured components.
Integrated Performance and Capability Analysis of Anticorrosive Cathodic Electrodeposition Coatings: Effect of Polymerization Variables
(2025) Peti, Damián; Stolárik, Gabriel; Vandžura, Radoslav; Gombár, Miroslav; Hatala, Michal
The presented research delivers a comprehensive evaluation of anticorrosive cathodic electrodeposition (CED) coatings through an integrated performance and process capability analysis—an approach that remains extremely limited in the literature, particularly in the context of statistically designed experiments (DoEs) applied to CED systems. This study therefore addresses a notable gap by focusing on the role of polymerization variables in determining coating quality through DoE to quantify the influence on coating thickness uniformity, adhesion integrity and impact resistance, while all other deposition parameters were rigorously controlled. Prior to coating application, all specimens were prepared and conditioned in accordance with ISO 1513:2010. Coating thickness was determined in compliance with ISO 2808:2019, adhesion was characterized by cross-cut methodology according to ISO 2409:2020 and dynamic mechanical resistance was evaluated using a falling-weight apparatus in accordance with ISO 6272-1:2011. The obtained datasets were subjected to statistical capability analysis within the PalstatCAQ environment, providing Cp, Cpk, Pp and Ppk indices in line with ISO 22514-7:2021 and IATF 16949:2016 requirements. Results evidenced non-linear dependencies of thickness formation on curing parameters, with potential capability indices (Cp > 1.8; Pp ≈ 1.4) indicating favorable process dispersion, while performance indices (Cpk < 0.5; Ppk < 0.4) revealed systematic mean shifts and deviations from normality confirmed by Shapiro–Wilk and Anderson–Darling tests. Adhesion testing demonstrated a direct correlation between curing conditions and interfacial bonding, reaching ISO Grade 0 classification. Complementary impact resistance assessments corroborated these findings, showing that insufficient curing induced extensive cracking and delamination. Furthermore, SEM–EDX analysis performed on Sample n.3 of X2 variable confirmed the chemical integrity and multilayered structure of the CED coating.
Comprehensive Analysis of Deposition Parameters and Energy-Dispersive X-Ray Spectroscopy Characterization in Cataphoretic Coating Processes
(2025) Fejko, Patrik; Peti, Damián; Dobránsky, Jozef; Gombár, Miroslav; Michalík, Peter
This research examines the inter-relationship between the deposition time, degreasing temperature, and applied voltage in the cataphoretic painting process, focusing on their cumulative effects on the thickness of the formed layers. A series of experiments was conducted, systematically varying deposition time effects through voltage levels (200 V to 300 V) and degreasing temperatures (40 ◦C to 80 ◦C). The results demonstrate that the maximum layer thickness is achieved at longer cataphoretic times, with significant thickness increments observed at optimal voltage levels. Conversely, the study reveals that lower degreasing temperatures lead to increased layer thickness, while elevated temperatures tend to diminish it. Notably, the thickness variations are consistent across different voltage applications, with a discernible threshold at which the layer thickness stabilizes. Additionally, energy-dispersive X-ray spectroscopy (EDX) was utilized to characterize the elemental composition of the cataphoretic layer, providing deeper insights into the coating structure and its relationship to process parameters. This work provides valuable insights into the optimization of cataphoretic processes, offering a framework for enhancing the quality and uniformity of coatings in industrial applications. The findings underscore the importance of the precise control over process parameters to achieve the desired material characteristics, thereby advancing the field of surface engineering and coating technologies.
Experimental Insights into Free Orthogonal Cutting of Stellite
(2025) Gombár, Miroslav; Harničárová, Marta; Valíček, Jan; Kušnerová, Milena; Tozan, Hakan; Mikuš, Rastislav
The effectiveness of a machining process can be determined by analysing the quality of the generated surface and the rate of tool wear. Stellite is highly challenging to machine, which is why it is primarily processed through grinding methods. This study concentrates on the impact of cutting parameters and tool wear (VBb, KBb) on the created surface roughness surface (Rt, Ra, Rz) during the orthogonal cutting of Stellite 6, which is overlaid on a steel surface, C45, prepared by means of HP/HVOF (JP-5000). The results indicate that the dominant influence on the change in the total roughness profile height value (Rt) is the mutual interaction of cutting speed and depth of cut at 16% (p < 0.000). The greatest impact on the change in the mean arithmetic deviation of the roughness profile (Ra) value is the interaction of cutting speed, tool front angle, and depth of cut with a 15% share (p < 0.000), as well as on the change in the Rz value (15%) and tool wear VBb (25%). This investigation lays the groundwork for potentially substituting the processing of flat surfaces with hardened layers created by thermal spraying (such as Stellite 6) with grinding or methods that offer greater efficiency from both economic and technological perspectives.
Turn Milling of Inconel 718 Produced via Additive Manufacturing Using HVOF and DMLS Methods
(2025) Povolný, Michal; Straka, Michal; Gombár, Miroslav; Hnátík, Jan; Kutlwašer, Jan; Sklenička, Josef; Fulemová, Jaroslava
Additive and coating technologies, such as high-velocity oxy-fuel (HVOF) thermal spraying and direct metal laser sintering (DMLS), often require extensive post-processing to meet dimensional and surface quality requirements, which remains challenging for nickel-based superalloys such as Inconel 718. This study presents the design and topology optimisation of a cutting tool with a linear cutting edge, capable of operating in turn-milling or turning modes, offering a viable alternative to conventional grinding. A non-optimised tool served as a baseline for comparison with a topology-optimised variant improving cutting-force distribution and stiffness-to-mass ratio. Finite element analyses and experimental turn-milling trials were performed on DMLS and HVOF Inconel 718 using carbide and CBN inserts. The optimised tool achieved significantly reduced roughness values: for DMLS, Ra decreased from 0.514 ± 0.069 µm to 0.351 ± 0.047 µm, and for HVOF from 0.606 ± 0.069 µm to 0.407 ± 0.069 µm. Rz was similarly improved, decreasing from 4.234 ± 0.343 µm to 3.340 ± 0.439 µm (DMLS) and from 5.349 ± 0.552 µm to 4.521 ± 0.650 µm (HVOF). The lowest measured Ra, 0.146 ± 0.030 µm, was obtained using CBN inserts at the highest tested cutting speed. All improvements were statistically significant (p < 0.005). No measurable tool wear was observed due to the small engagement and the use of a fresh cutting edge for each pass. The resulting surface quality was comparable to grinding and clearly superior to conventional turning. These findings demonstrate that combining topology optimisation with a linear-edge tool provides a practical and efficient finishing approach for additively manufactured and thermally sprayed Inconel 718 components.
Analysis of Parameters of Laser-Induced Periodic Microstructures (LIPSS) on the Surface of Stainless Steel Using Autocorrelation Functions
(2025) Saprykina, Emiliia; Dobrotvorskyi, Sergiy; Aleksenko, Borys; Trubín, Dmytro; Moskal, Denys; Martan, Jiří
In modern mechanical engineering, the control of surface quality of components, which directly affects their operational characteristics, is becoming increasingly important. One of the key aspects is the analysis of surface microstructure, particularly its periodicity, as it determines properties such as wear resistance and corrosion resistance. Laser processing is one of the promising technologies that allows the formation of regular microstructures, such as LIPSS (Laser-Induced Periodic Surface Structures). Despite extensive research, the mechanism of LIPSS formation remains not fully understood, and the results often show variable periodicity and orientation. To accurately analyze these structures, mathematical and statistical methods, such as two-dimensional autocorrelation analysis (ACF) and fast Fourier transform (FFT), are required. This study proposes a methodology for evaluating the periodicity of microstructures obtained during laser treatment of metallic samples, using digital video microscopy. The application of two-dimensional autocorrelation and spectral analysis within the Gwyddion environment ensures reproducible and objective assessment of microstructures, while demonstrating the effectiveness of ACF for surface topography analysis. The obtained data show the presence of pronounced periodicity in the studied microstructure and confirm the complexity of the LIPSS formation mechanisms, contributing to accurate quantitative analysis and adaptive control of laser modification processes.
Testing and evaluation of mechanical properties of C45 steel with bainitic structure
(2024) Sasiadek, Michal; Woźniak, Waldemar; Melichar, Martin
Purpose: The article aims to investigate the mechanical properties of C45 steel with a previously constituted bainitic structure, due to its widespread use in the machine industry. Design/methodology/approach: The input ferritic-pearlitic structure of steel was subjected to heat treatment in the form of quenching and tempering in order to obtain a bainitic structure. Tempering was carried out at different temperature and time values. It allowed various properties of the steel samples to be obtained, which were subsequently subjected to tensile strength and hardness testing. In addition, metallographic images of the resulting structures were taken. Findings: The results obtained from the tests were compiled in tabular form. Based on the results, correlations were observed in the tensile strength and hardness of the tested steel relative to various parameters of the hardening and tempering processes. Research limitations/implications: The strength properties testing of C45 steel with a bainitic structure was limited to determining the yield strength Re, tensile strength Rm, elongation A, and microhardness HV0.5. Practical implications: The tests confirmed the possibility of controlling heat treatment process parameters to achieve the desired mechanical properties of the steel. This may contribute to the practical control of the steel’s properties due to economic aspects and functional requirements. Originality/value: The article is primarily addressed to industrial practice, i.e., manufacturers of machine parts made of medium-carbon steel, due to the reduction in heat treatment time and energy consumption costs while maintaining the steel’s machinability and strength properties. © International OCSCO World Press. All rights reserved. 2024.
The Effect of Drag Finishing on Additively Manufactured Customized Dental Crowns
(2025) Cosma, Cosmin; Melichar, Martin; Libu, Stelian; Popan, Alexandru; Contiu, Glad; Teusan, Cristina; Berce, Petru; Balc, Nicolae
Cobalt–chromium (CoCr) alloys are frequently used to produce customized dental applications such as crowns, bridges, or prostheses. These medical products have anatomical forms, and can be effectively manufactured using the laser-based powder bed fusion (PBF-LB/M) technique. A majordisadvantage of this approach is the extended time required to refine the resultant surface. The purpose of this research is to reduce the surface roughness of PBF-LB/M/CoCr dental crowns by adopting drag finishing (DF) technology. To evaluate the impact of this automatic post-processing, surface roughness measurements and geometrical investigations were undertaken. The microstructure was characterized using scanning electron microscopy (SEM), and the chemical composition was verified by energy-dispersive X-ray spectroscopy (EDAX). On outside surfaces, the DF post-processing decreased the initial surface roughness by 70–90%. The dental crown’s surface roughness value after DF post-processing was comparable to that of the basic form (cylinder). The lowest roughness was obtained with DF3 post-processing (Ra~0.60 μm). The inner surfaces were limitedly finished. The 3D surface texture showed that the DF method reduced the height of peaks, uniformizing the surfaces. CMM work compared the deviations between the virtual model and the printed samples before and after DF post-processing. This analysis revealed that dimensional deviations were reduced on the outside crown walls, ranging from +0.01 to +0.05 mm. The laser parameters and the heat treatment applied increased the hardness of CoCr crowns to 520 HV, but the proper DF conditions identified reduced the surface roughness and improved the accuracy.
Comprehensive Experimental Analysis of the Effect of Drilled Material on Torque Using Machine Learning Decision Trees
(2025) Hnátík, Jan; Fulemová, Jaroslava; Sklenička, Josef; Gombár, Miroslav; Vagaská, Alena; Sýkora, Jindřich; Lukáš, Adam
This article deals with drilling, the most common and simultaneously most important traditional machining operation, and which is significantly influenced by the properties of the machined material itself. To fully understand this process, both from a theoretical and practical perspective, it is essential to examine the influence of technological and tool-related factors on its various parameters. Based on the evaluation of experimentally obtained data using advanced statistical methods and machine learning decision trees, we present a detailed analysis of the effects of technological factors (fn, vc) and tool-related factors (D, εr , α0, ωr) on variations in torque (Mc) during drilling of two types of engineering steels: carbon steel (C45) and case-hardening steel (16MnCr5). The experimental verification was conducted using CTS20D cemented carbide tools coated with a Triple Cr SHM layer. The analysis revealed a significant influence of the material on torque variation, accounting for a share of 1.430%. The experimental verification confirmed the theoretical assumption that the nominal tool diameter (D) has a key effect (53.552%) on torque variation. The revolution feed (fn) contributes 36.263%, while the tool’s point angle (εr) and helix angle (ωr) influence torque by 1.189% and 0.310%, respectively. No significant effect of cutting speed (vc) on torque variation was observed. However, subsequent machine learning analysis revealed the complexity of interdependencies between the input factors and the resulting torque.
Research of Tribological Properties of 34CrNiMo6 Steel in the Production of a Newly Designed Self-Equalizing Thrust Bearing
(2020) Urban, Marek; Monková, Katarína
There are many cases when in large power equipment (such as a turbine or compressor) asymmetrically loading on bearings due to thermal deformations, production inaccuracies, or simple deflection of the shaft occurs. This asymmetrically loading means misalignment of rotor against stator in angle more than several tenths of a degree and it has an influence on a journal and thrust bearings. Over the last few years, thanks to increasingly precise manufacturing, solutions that can eliminate this phenomenon have been revealed. In the case of the thrust bearing, it is a system of very precise manufactured levers, which are in close contact each to other, so they have to be not only properly designed from the geometrical point of view but the important role plays a quality of the functional surfaces of these levers. The article deals with the surface treatment effect on tribological properties of 34CrNiMo6 steel used for the production of bearing levers, which are the critical parts of a newly developing self-equalizing thrust bearing. The samples with cylindrical and plate shapes were produced from 34CrNiMo6 steel as representatives of the most suitable geometries for contact surfaces. All samples were heat-treated. The surfaces of some samples were treated by electroless nickel plating or nitriding, some of the samples were treated by tumbling. Gradually, the surface roughness, microhardness, metallographic analysis and the influence of selected types of surface treatments on the wear for individual samples were evaluated within the research presented in the article. As the testing methods for evaluation of tribological properties were selected Pin-on-disc test and frequency tribological test. The results showed that the best tribological properties achieved samples treated by electroless nickel plating compared with the nitrided or only heat-treated samples.
The Influence of the Amount of Technological Waste on the Performance Properties of Fibrous Polymer Composites
(2024) Dobránsky, Jozef; Gombár, Miroslav; Fejko, Patrik
The objective of the experimental analysis was to assess the impact of the reuse of technological waste (recyclate) on the selected performance properties of the fibrous polymer composite used to produce components for the automotive industry by injection molding technology. Polyphthalamide (PPA), which belongs to a group of high-tech polymers, was chosen as the analyzed material. In accordance with the set goals, the rheological, mechanical, and structural properties of the material were evaluated using ANOVA analysis in the experimental part of the work, depending on the mass ratio of the recycled material added to the virgin material. The influence of the proportion of recycled material on the lifetime of moldings by the method of their exposure at an elevated temperature for a defined time was also assessed. During the research, it was found that at a concentration of up to 40 wt. % of recyclate, its mechanical properties do not change significantly. At a concentration of 50 wt. %, there is a rapid decrease in mechanical properties. In the long term, it can also be said that the addition of recyclate significantly affects the service life of the components. No significant changes in morphology were observed during the analysis of structural properties.
Methodology of rotation of general surfaces
(2024) Lehner, Radek; Valdman, Jan; Zídková, Helena
When parts are machined, especially on heavy machine tools, an accurate description of the rotations around the geometric axes is required. The work adds the concept of rotation around the machine and the workpiece axes. Both types of rotation in mechanics are related to internal and external rotations, which we describe in detail. We show how both types convert to each other and how conversion formulas are derived. The resulting conversions are formalized as functions in the C and MATLAB programming languages. The result of this mathematical description will be transferred to a new transformation cycle that can be used on machines as a standard.
Analysis of the effect of pretreatment on the overall damage of the coating created by the cataphoretic coating
(2024) Fejko, Patrik; Dobránsky, Jozef; Straka, Ľuboslav; Gombár, Miroslav
Aluminum and its alloys are essential in construction due to their lightweight nature and recyclability. To enhance durability, protection against corrosion is vital, with cataphoretic painting being particularly effective. This study evaluated the damage rate of cataphoresis coatings on AW 1050 H24 aluminum, focusing on the impact of different degreasing solutions. By analyzing temperature, concentration, and deposition time, the study found that concentrations above 5.25 % degrade surface quality due to aluminum dissolution, while temperatures between 37 °C and 50 °C are optimal. At higher temperatures, shorter deposition times improve quality, whereas longer times lead to defects.
Determination of the brittleness of glass fibers on selected mechanical and rheological properties of the polymer composite
(2024) Miščík, Stanislav; Dobránsky, Jozef; Gombár, Miroslav; Čep, Robert
The paper deals with the influence of the brittleness of glass fibers on the selected performance properties of the fibrous polymer composite. Understanding the fatigue behavior of fiber-reinforced plastics is desirable for exploiting their features in safe, durable, and reliable industrial components. Based on the proposed methodology, it is possible to assess the impact of material reuse on selected mechanical and rheological properties. To verify the methodology by experimental analysis, homopolymer PP reinforced with chemically grafted glass fiber (30 wt%) was selected. The proposed methodology was subsequently verified by experimental analysis and evaluated statistically. The morphology of the fracture surfaces was evaluated, and the fiber-polymer matrix adhesion was monitored at the interface of the fracture surfaces. Based on the measured and evaluated values and fracture surfaces, we can say that the brittleness of the fibers significantly affects the performance properties of the tested polymer composite.
The effect of degreasing temperature on the thickness of the formed layer created by cataphoretic painting
(2024) Peti, Damián; Dobránsky, Jozef; Zajac, Jozef; Gombár, Miroslav
The article investigates the impact of degreasing temperature in the degreasing mixture PRAGOLOD 57N on cataphoretic painting using design of experiments (DoE). Key technological factors such as degreasing deposition time, concentration, cataphoretic deposition time, and voltage are examined for their effect on the thickness of the formed anti-corrosion layer. Cataphoretic painting, an economical and eco-friendly method, is widely used for treating metal parts in automotive and engineering industries. The study involves testing 88 samples, with thickness measurements taken via Elcometer 456C according to the ISO standards and graphical analysis performed using statistical software to optimize the process.
Evaluation of recycled and reused metal powders for DMLS 3D printing
(2024) Svozilová, Simona; Zetková, Ivana; Marin, Juan Felipe Santa; Garay, Jesús Arturo Torres
Metal powders for additive manufacturing are expensive and producing new ones from mined metals has a negative ecological impact. In this work, recycled and reused metal powders from MS1 steel for Direct Metal Laser Sintering (DMLS) 3D printing were evaluated in the laboratory. The powders were recycled by melting followed by gas atomizing. Virgin, recycled and reused metal powders were evaluated using Scanning-Electron Microscopy (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS), X-Ray Diffraction (XRD), metallography analysis, microhardness measurements, Particle Size Distribution (PSD), shape factor by Digital Image Processing (DIP) and flowability testing. The results showed that the particle distribution was modified after recycling. Kurtosis analysis revealed a reduction from -0,64 for virgin powder to -1,29 for recycled powders. A positive skewness was obtained a consequently, smaller particles were found in recycled powder. The shape factor was also modified and changed from 1,57 for virgin powders to 1,28 for recycled powders. The microstructure also changed and austenite was found in recycled powders. The microhardness of recycled powder decreased by 39% compared to the virgin powder. Recycled powders did not flow using two different funnels to evaluate their flowability. The flowability of used powder was reduced from 4,3 s to 2,9 s.
Experimental Analysis of Effect of Machined Material on Cutting Forces during Drilling
(2024) Sklenička, Josef; Hnátík, Jan; Fulemová, Jaroslava; Gombár, Miroslav; Vagaská, Alena; Jirásko, Aneta
Current research studies devoted to cutting forces in drilling are oriented toward predictive model development, however, in the case of mechanistic models, the material effect on the drilling process itself is mostly not considered. This research study aims to experimentally analyze how the machined material affects the feed force (Ff ) during drilling, alongside developing predictive mathematical–statistical models to understand the main effects and interactions of the considered technological and tool factors on Ff. By conducting experiments involving six factors (feed, cutting speed, drill diameter, point angle, lip relief angle, and helix angle) at five levels, the drilling processof stainless steel AISI1045 and case-hardened steel 16MnCr5 is executed to validate the numerical accuracy of the established prediction models (AdjR = 99.600% for C45 and AdjR = 97.912% for 16MnCr5). The statistical evaluation (ANOVA, RSM, and Lack of Fit) of the data proves that the drilled material affects the Ff value at the level of 17.600% (p < 0.000). The effect of feed represents 44.867% in C45 and 34.087% in 16MnCr5; the cutting speed is significant when machining C45 steel only (9.109%). When machining 16MnCr5 compared to C45 steel, the influence of the point angle (liprelief angle) is lower by 49.198% (by 22.509%). The effect of the helix angle is 163.060% higher when machining 16MnCr5.
Influence of Laser Treatment of Ti6Al4V on the Behavior of Biological Cells
(2024) Syrovátka, Šimon; Kožmín, Pavel; Holešovský, František; Šorm, Martin
This article explores the enhancement of material surface properties of Ti6Al4V, potentially applicable to dental implants, through ultra-short pulse laser systems. This study investigates potential connections between surface wettability and biocompatibility, addressing the challenge of improving variability in material properties with specific laser treatment. Several designed microstructures were manufactured using a picosecond laser system. After that, the wettability of these structures was measured using the sessile drop method. The basic behavior and growth activity of biological cells (MG-63 cell line) on treated surfaces were also analyzed. While the conducted tests did not conclusively establish correlations between wettability and biocompatibility, the results indicated that laser treatment of Ti6Al4V could effectively enlarge the active surface to better biological cell colonization and adhesion and provide a focused moving orientation. This outcome suggests the potential application of laser treatment in producing special dental implants to mitigate the issues during and following implantation.
Inverse dependence of heat accumulation on pulse duration in laser surface processing with ultrashort pulses
(Elsevier, 2023) Moskal, Denys; Martan, Jiří; Honner, Milan; Ballardin Beltrami, Carlos; Kleefoot, Max Jonathan; Lang, Vladislav
Délka laserového pulzu je jedním z důležitých parametrů, který je schopen dramaticky změnit účinnost ablace. Kratší doba trvání laserového pulzu vede k hlubšímu transportu absorbované energie v podpovrchových vrstvách materiálu. Ultrarychlé a nerovnovážné procesy dokážou pozoruhodně ovlivnit zbytkovou energii, která se po ablaci akumuluje v hlubších podpovrchových vrstvách. Na druhé straně nežádoucí vysoká akumulace tepla vede k přehřívání materiálu s povrchovou oxidací, vznikem kapalné fáze a v důsledku toho k nízké kvalitě zpracování. V tomto článku byl poprvé experimentálně hodnocen vliv délky laserového pulsu na hodnotu akumulace tepla. Akumulace tepla byla měřena vysoce citlivým rychlým infračerveným detektorem. Výsledky byly prezentovány v porovnání s analýzou struktury povrchu, rychlostí ablace materiálu a optickou odrazivostí. Byla zjištěna neočekávaná inverzní závislost akumulace tepla na délce laserového pulzu. Optimální trvání laserového pulsu blízko 1 ps odpovídá maximální hodnotě akumulace tepla a také nejvyšší účinnosti ablace na rozdíl od delších laserových pulsů. Stejná optimální hodnota trvání pulsu byla detekována pro nízkofrekvenční (250 kHz) a pro vysokofrekvenční (1 MHz) režimy laserového zpracování povrchu. Maximální hodnota akumulace tepla byla očekávána při nejdelších laserových pulzech. Výsledky jsou diskutovány z pohledu dvouteplotního modelu.
Ergonomie jako významná součást age managementu
(ERC, 2022) Pokorná, Václava
Demografický vývoj populace v Evropě naznačuje trend, který předpokládá, že počet lidí ve věku nad 60 let se bude v příštích desetiletích ve světě zvyšovat asi o 2 miliony ročně. Tato prognóza poukazuje na situaci, kdy by se mohl počet obyvatel v produktivním věku snižovat a tím začne zároveň klesat počet zaměstnanců. Problém stárnoucí pracovní síly je celosvětová výzva k zamyšlení a je nutné se začít včas zabývat nastavením pracovních podmínek pro starší zaměstnance. Především nacházením možností jejich uplatnění v profesích, které to umožňují. Posláním ergonomie, jako samostatné vědecké disciplíny, je analyzovat pracovní podmínky pro člověka v souladu s jeho fyzickou a psychickou výkonností. Ergonomie se tím stává významnou součástí age managementu, jehož základní filozofií je nutnost nastavení takových podmínek pro práci starších zaměstnanců, aby požadavky byly v souladu s jejich schopnostmi. V článku je představen základní koncept ergonomického auditu pracoviště jako nezbytná součást pro možný výběr sdíleného místa v dané organizaci

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