Michal Krbata

This study evaluates the effect of different precipitation-hardening regimes on the microstructure, hardness, and tribological behaviour of W720 maraging steel. Experimental specimens were aged at temperatures ranging from 460 to 490 °C for 3–16 h following solution annealing. Tribological tests were performed using the Ball-on-Flat method under dry sliding conditions against a G40 steel ball. The worn surfaces were analysed using LSCM, SEM, and EDS. Aging increased the hardness from 323 HV1 to 580–606 HV1 and reduced the coefficient of friction from approximately 0.75 to 0.63–0.71. The lowest nominal specimen wear volume was measured for the as-received, solution-annealed W720 condition (0.011 mm³), followed by HT490_6 (0.012 mm³); these values were compared descriptively without inferential statistical testing. However, the reference specimen produced a narrow, locally deepest wear track and caused the highest wear of the counter-body. The highest wear volume of the specimen was recorded for HT480_3 (0.027 mm³), while HT460_8x2 combined the highest hardness and the lowest coefficient of friction with a high wear volume. The dominant wear mechanism was a combination of abrasive grooving, adhesive damage, and tribo-oxidation. The results demonstrated that the tribological resistance of W720 is not governed by hardness alone, but rather by the interplay between microstructure, wear-track geometry, wear-product morphology, and the distribution of wear between the specimen and the counter-body.

This paper estimates the total electromagnetic load in the passenger compartment. A computational model is proposed based on the numerical solution of Maxwell’s equations and the specular reflection method for near-field emitters, accounting for the shielding properties of the metal body and attenuation through the glazing apertures. Theoretical calculations and field measurements were performed using a spectrum analyzer (Narda NBM-550) and isotropic probes over the frequency range from 10 Hz to 3 GHz during various operating modes of the power plant and auxiliary electrical equipment. The comprehensive measurement campaign utilized two complementary metrological systems to cover the entire spectrum: a dedicated Narda EHP-50F isotropic analyzer was deployed for the low-frequency domain (10 Hz–100 kHz), while high-frequency electromagnetic and radiofrequency components (100 kHz–3 GHz) were acquired using a Narda NBM-550 broadband field meter equipped with isotropic electric (EF-0391) and magnetic (HF-3061) probes. The maximum low-frequency magnetic induction (B max = 2.4 μT) was recorded near the driver’s pedal unit and the engine shield, attributable to generator field leakage and ignition-system transients. In the high-frequency range (2.4 GHz), resonant effects of the metal body caused standing-wave interference nodes, producing electric field strength peaks of 8.5–9.5 V/m. Although the recorded field parameters are within the limits specified by ICNIRP and national sanitary standards, they pose a chronic exposure risk to drivers traveling long distances. Design recommendations are proposed to optimize the wiring topology and local shielding.

This paper presents an analytical and simulation-based approach to estimating the probability of failure of technical components using a stress – strength interference model. The proposed methodology integrates the statistical processing of experimental or operational data with probabilistic modeling and simulation implemented within the MATLAB environment. The input variables – operational stress and structural resistance – are described using appropriate probability distributions, enabling the evaluation of their mutual interaction and its impact on system reliability. The developed simulation framework allows for both graphical and numerical assessment of the interference region, which represents critical states in which failure may occur. The influence of variability in input parameters, particularly the standard deviation, is analyzed in order to evaluate the sensitivity and robustness of the model. The results demonstrate that increased dispersion of stress and resistance significantly affects the probability of failure and the system safety margin. The application of the proposed method to a selected technical component revealed a failure probability exceeding the admissible limit, confirming the need for optimization measures. Adjustments to the resistance characteristics led to a partial improvement in reliability; however, additional design or operational modifications were required to meet the prescribed requirements. The main contribution of this work lies in the development of a flexible simulation tool that supports reliability assessment, sensitivity analysis, and decision-making processes in engineering practice. This approach is particularly beneficial under conditions of limited availability of empirical data and can be effectively applied in industries such as automotive engineering, where stochastic loading and material variability play a crucial role in system reliability.

The development of cycling transport in urban areas creates an increasing need for reliable data collection on the volume, direction and characteristics of cyclist movement. Data on the number of cyclists on cycle routes represent a fundamental input for planning new infrastructure, evaluating the use of existing routes, designing safety measures and optimizing traffic management. The aim of this article is to provide an overview of technologies used for bicycle traffic counting and bicycle traffic monitoring. Attention is focused on methods such as manual counting, video recording, computer vision systems, inductive loop detectors, pneumatic tube counters, infrared sensors, radar sensors, LiDAR sensors and crowdsourced mobile data. The individual methods are compared in terms of accuracy, costs, technical requirements, suitability for long-term operation, ability to classify users and applicability to different types of cycling infrastructure. The review shows that there is no universally most suitable technology. The choice of method must be based on the purpose of measurement, required accuracy, and the type of cycle route, monitoring duration, available budget and privacy requirements. The most promising direction is the combination of fixed automatic sensors, image-based or LiDAR-based systems, and supplementary mobile data.

This study explores the development of low-friction, water-based coatings tailored for industrial applications in pharmaceutical glass packaging. The study focuses on scalable deposition strategies to obtain durable low-friction coatings suitable for industrial implementation. To balance mechanical performance and application efficiency, two different application approaches based on a two-component coating (aminosilane primer and lubricant) were investigated. In the first case, the coating is deposited in two steps, while in the second, a single deposition step is used. Characterization through contact-angle measurements and X-ray photoelectron spectroscopy confirmed successful deposition of the primer on the glass surface. Scratch resistance tests revealed an increase in the critical load for fracture initiation from 4.5 N for uncoated glass to 6.5 N for the best-performing coating, indicating improved resistance to surface damage. Friction performance was assessed via tribological tests, which demonstrated that the primer–lubricant coatings achieved the lowest coefficient of friction (approximately 0.2), compared with uncoated glass (stabilizing at approximately 0.3 after an initial value of 0.5) and lubricant-only coatings (approximately 0.4–0.5), confirming the beneficial role of the primer in the coating system. Representative profilometry measurements indicated sub-micrometric coating thicknesses, while UV–Vis measurements confirmed that the coatings preserved the high optical transparency of the glass substrate, with average visible transmittance values above 90%. Furthermore, the successful implementation of the coating using an automated spray system demonstrates its potential for scalable industrial production. These findings support the potential of environmentally sustainable water-based coatings for pharmaceutical glass packaging by combining improved mechanical performance with preserved optical transparency and compatibility with scalable spray deposition.

This study investigates the tribological performance of three commercial PTFE-based Xylan^® coatings—Xylan^® 1425, Xylan^® 1052, and Xylan^® 1010—applied to 18CrNiMo7-6 steel under dry sliding conditions. Ball-on-Disk tests were conducted at normal loads of 5, 7.5, and 10 N, wear-track radii of 12, 16, and 20 mm, and corresponding sliding velocities of 0.31–0.52 m·s⁻¹. The tribological evaluation was complemented by measurements of coating thickness, surface roughness, nanoindentation, wear-track profilometry, scanning electron microscopy, EDS mapping, and post-test cross-sectional microscopy. All coatings reduced the coefficient of friction from approximately 0.49–0.64 for the uncoated steel to 0.09–0.13, corresponding to an average reduction of 78–80%. Xylan^® 1425 exhibited the highest nanohardness of 57.02 MPa, the highest reduced elastic modulus of 3.33 GPa, and the most favorable elastoplastic indices. It also achieved the lowest wear, with a volumetric loss of approximately 0.03 mm³ under the most severe conditions, representing a reduction of more than 99% compared with the substrate. Xylan^® 1010 provided the lowest friction but showed pronounced plastic deformation, whereas Xylan^® 1052 exhibited fragmentation and increased wear. Post-test cross-sectional microscopy confirmed local exposure of the steel substrate in both coatings. Overall, Xylan^® 1425 provided the best balance of low friction, mechanical stability, coating continuity, and wear resistance.

The rapid evolution of connected and autonomous vehicles has significantly increased the importance of automotive telemetry as a fundamental component of intelligent transportation systems. Modern vehicles continuously generate large volumes of operational, environmental, and behavioral data that must be transmitted, processed, and analyzed in real time to support applications such as predictive maintenance, remote diagnostics, cooperative mobility, and autonomous driving. The growing demand for reliable and large-scale data exchange has highlighted the critical role of advanced communication infrastructures in connected mobility ecosystems. This review provides a comprehensive overview of automotive telemetry technologies with a particular focus on communication solutions enabling long-range data transmission. The study examines the architecture of automotive telemetry systems, connected vehicles, and the Internet of Vehicles, followed by an analysis of Vehicle-to-Everything (V2X) communication, fifth-generation (5G) mobile networks, satellite communication systems, and emerging hybrid 5G–satellite architectures. In addition, the review discusses Software Defined Vehicles, Digital Twin technologies, artificial intelligence integration, and cybersecurity challenges associated with highly connected transportation environments. The analysis demonstrates that no single communication technology can satisfy all requirements of future intelligent mobility systems. Instead, hybrid communication architectures combining terrestrial and non-terrestrial networks are expected to provide the reliability, coverage, scalability, and low-latency performance required for next-generation connected transportation. Finally, key research challenges and future development directions are identified, emphasizing the growing convergence of telemetry, communication networks, artificial intelligence, digital twins, and cybersecurity within future connected mobility ecosystems.

The development of modern types of ammunition and the increasing requirements for ballistic protection have created a need for armour systems capable of providing a high level of protection while maintaining an acceptable weight. Traditional homogeneous armour systems, primarily based on steel materials, have gradually become insufficient against high-velocity projectiles and shaped-charge munitions, leading to the development of multilayered and hybrid protective systems that combine materials with different mechanical properties. The aim of this review article is to systematically analyse the development of armour systems, from homogeneous metallic armour to modern multilayered and hybrid composite configurations, and to identify the key mechanisms responsible for increasing ballistic resistance while reducing areal density. The article synthesises and critically evaluates findings published in the available scientific literature focused on metallic, ceramic, polymeric, and hybrid armour systems. Particular attention is paid to mechanisms of energy absorption, projectile fragmentation, stress redistribution, and interactions between individual layers under dynamic loading. The analysis of published studies indicates that multilayer composite armour systems achieve higher ballistic efficiency than homogeneous systems due to the synergistic action of several protective mechanisms. Ceramic layers provide projectile destabilisation and fragmentation, while metallic and polymeric backing layers effectively absorb the residual energy and capture the resulting fragments. The findings also highlight the importance of armour architecture, the sequence of individual layers, and the quality of interfaces between materials, all of which significantly affect the resulting ballistic resistance, multi-hit capability, and the ratio between the level of protection and system weight. Current trends in armour technology development are directed towards the optimisation of multilayer configurations, the use of hybrid materials, bio-inspired architectures, graded structures, and advanced manufacturing technologies. The objective is to develop lightweight multifunctional armour systems that provide a high level of protection without a significant increase in areal density.

Carbon fibre-reinforced polymer (CFRP) composites represent promising lightweight materials for automotive powertrain systems, where increasing demands for weight reduction, energy efficiency, and emission reduction are driving the replacement of conventional metallic components. However, automotive powertrain environments expose CFRP materials to elevated temperatures, cyclic mechanical loading, chemical exposure, and tribological interactions, creating complex degradation conditions that significantly influence long-term durability and reliability. This review systematically analyzes CFRP composites for automotive powertrain applications, focusing on the relationship between operational requirements, material selection, reinforcement architecture, manufacturing technologies, and degradation mechanisms. High-performance thermoplastic systems such as CF/PEEK, CF/PPS, and CF/PEKK are critically compared with conventional thermoset composites. CF/PEEK systems demonstrate superior thermomechanical stability, maintaining significant mechanical performance at temperatures approaching 250 °C and tensile strengths of approximately 1400–1600 MPa, whereas CF/PPS composites provide a more economically efficient compromise between thermal resistance, chemical stability, manufacturability, and recyclability for medium-temperature applications. The review further analyzes dominant degradation mechanisms, including creep deformation, fatigue damage, delamination, fibre–matrix interface degradation, and tribological wear. CFRP degradation is shown to result from the interaction of multiple coupled mechanisms rather than from isolated material failure modes. Tribological wear rates typically range from 10⁻⁶ to 10⁻⁵ mm³/(N·m), while creep–fatigue interactions may reduce component lifetime by up to 40–60% under combined thermomechanical loading. Advanced design strategies, including fibre orientation optimization, laminate architecture tailoring, thickness gradation, and hybrid metal–composite structures, are evaluated together with major manufacturing technologies such as injection moulding, compression moulding, overmoulding, automated fibre placement, and additive manufacturing. The presented review establishes an integrated framework linking material systems, operating conditions, manufacturing processes, and durability requirements for automotive powertrain applications. The analysis demonstrates that no universal CFRP system exists for all powertrain components and that optimal material selection requires balancing thermal stability, fatigue resistance, tribological performance, manufacturability, recyclability, and economic constraints according to the specific operating conditions of each component category.

This paper aims to analyse the microstructure and properties of the titanium- and boron-alloyed high-carbon medium-manganese 140Mn6Cr3TiB steel deposit before and after high-frequency mechanical impact (HFMI) treatment. XRD, SED, and EDS analyses were applied to evaluate the microstructural peculiarities of the studied deposit. Nanoindentation and scratch/sliding tests respectively revealed distinct correlations between the phase composition and the deformation/wear behaviour. HFMI results in the formation of the strain-induced ε- and α’-martensites (~66% and 3–6%, respectively), a significant grains/crystallites refinement (down to 31–54 nm), and dislocation density, which support essential hardening (by ~50%). The HFMI regime (load = 100 N, amplitude = 10 µm, and time = 60 s) was found to be the best, which led to the enhanced wear resistance (decreased wear volume) by ~4 times. The heterogeneous nature of the steel deposit creates a “shield-and-buffer” effect, where the hard eutectic framework resists penetration and tough matrix prevents brittle failure, maintaining a high tolerance to abrasion damage. The HFMI-hardening changed the wear mechanism from the ‘wedge/pile-up’ formation to ploughing. Thus, the HFMI shows a good efficiency in finishing the protective medium-manganese steel deposits of enhanced wear resistance to prolong the operation life of responsible parts.