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In this work, the microstructure and properties of the first-Republic Czechoslovak circulation coins were studied. The variety of the coins at that time was shown. Significant differences in microstructure in the direction of forming and in the normal direction to the surface direction have been confirmed. For some coins, visible features of recrystallization were shown, which suggests the coinage at higher temperatures. The chemical composition of coin alloys was also studied. In most cases, it was consistent with the declared chemical composition by mint. Significant differences in the hardness of the coins were found, which confirmed the different experience of numismatics with the abrasive resistance and the preservation of different coins. The quality of the design and the material composition of the coins confirm the long-standing experience with coinage in the Czech lands, despite the fact that, after the Austro-Hungarian Empire, the mining industry was struggling with big problems (eg stolen raking machines, lack of Czech mining experts). The first-Republic circulation coins represent the best in the history of the Czech and Czechoslovak coinage industry.

This article deals with the experimental investigation of the influence of tire pressure on fuel consumption and tire life in passenger cars. Using laboratory and real-world operational measurements, the dependence between tire pressure and temperature, contact patch size, tread wear, and changes in driving characteristics was analyzed. The results show that even slight deviations from the prescribed pressure can lead to increased fuel consumption, shortened tire life, and reduced driving comfort and safety. The article also draws attention to the insufficient use of pressure monitoring systems in practice and points to the economic and ecological impacts of underinflation. The experimental data are supplemented with graphs and tables that demonstrate the influence of pressure on tire behavior during driving.

The paper deals with stress of forming dies in complex conditions of concrete processes during their service life. Possibilities of assessment and prediction of tool service life based on comparative analysis of dynamic fatigue and abrasive wear are presented. Classical solution of dynamic fatigue is complemented by analysis of the situation of cyclic contact of rotating instruments. In this case super-position of cyclic pressure effect dominates, as well as abrasion on the surface of the functional surfaces of the rotating forming tool. Specific in this case is the different speed in the contact line and also the dynamics of development of size, shape and localisation of the surface exposed to wear by cyclic compressive stress. The solution is demonstrated on examples of different forms of wear of forging and rolling tools. The results of a comprehensive predictive analysis can be applied at designing of technological chains of forming operations.

The features of quality, which is an ambiguous, gradual and very subjective concept, cause that there is no one absolute standard for it. Scientists are looking for ways of its evaluation and improvements of the existing methods. It relates to various areas, but at the same time it is also complex and multi-faceted. There are so many definitions of quality that are constantly evolving. In the paper two meth-ods Servqual and Servperf to assess the quality of teaching services were used. The aim of the paper was to compare the results of the service quality analysis with use of both methods and to indicate the differences between them. It was also checked whether conclusions regarding the quality of ser-vices differ depending on the used research method. The Servqual method takes into account the individual expectations of the respondents, which may affect the assessment of the actual service. It is more complicated, but the results are more adequate to the specifics of the service. It was shown that in one of the areas the results concerning the quality of teaching services differed significantly depending on the used method. However, it is not yet clear which of the two scales is a better meas-ure of service quality.

The article deals with the wear of the blades of the delimber device of harvester head. An input analysis of the materials of the fixed knife and movable arm parts was performed. It consisted of chemical analysis, evaluation of microstructure and hardness measurement by HRC and HB methods. The original welded joint was analyzed, which ensured the connection of the blade and the fixed, resp. movable arm mechanism. Based on the findings, two blade replacement solutions have been proposed. The first was the application of hard metal by an OK 84.58 electrode and second use HARDOX 450 by welding with a fixed part or a mechanical gripping with screws. This was recommended based on previous research at the Faculty of Technology. The hardnesses of the original blade material were compared with the proposed solutions. The correctness of the proposed methods will be verified in the future and in operation.

When diamond scribing knives are used to grind silicon wafers at ultra-high speeds, slight changes in the structure of the diamond scribing knives and changes in the grinding parameters will have a large impact on the processing accuracy and appearance of the silicon wafers. In order to reduce the defective rate of silicon wafers, improve the service life of diamond scribing knives and grinding efficiency. To address this issue, the working mechanism of the scribing knife grinding is analysed in the paper, the influence of spindle speed and feed rate on the quality of the silicon wafer slit when the scribing knife is grinding is studied, and the chipping of silicon wafers is observed through the scanning electron microscope and optical microscope, so as to analyse the shape of the cross-section, length of the cutting edge, concentration of diamond particles in the cutting edge, thickness of the cutting edge and determine the structure of the scribing knife, and to test its influence on the silicon wafer slit by means of the grinding experiments. The structure of the scribing knife was determined, and its influence on the quality of silicon wafer slit was tested by grinding experiment. The results show that the wear rate of diamond particles, slit quality and processing efficiency of the scribing knife are optimal when grinding silicon wafers at 50,000 r/min and 60-80 mm.sec^-1. The above study can help to further understand the wear mechanism of the scribing knife in the process of ultra-high-speed grinding of silicon wafers, improve the machining efficiency, and prolong the service life of the tool.

The push-type rotary steerable core bearing has high load capacity and high precision, and has been widely used in oil and gas drilling field. Its service life is difficult to predict due to various complex working conditions. Based on the finite element method, this paper establishes a three-dimensional rotating guide mandrel model to calculate and analyze the mechanical simulation of the guide mandrel under different working conditions, and establishes the corresponding life prediction model to predict its life. The results show that reducing the torque and speed in the range of drilling requirements is conducive to improving the overall life of the spindle, and the life matrix and life distribution are consistent with the characteristics of S-N curve, which is consistent with the characteristics of high cyclic stress of the spindle. The research results can be used to reliably predict the life of the push-type rotary steering mandrel and simulate its working state with high precision. This data is critical for reliability analysis and design optimization.

The introduced work deals with the microscopic analysis of metallographically prepared selected metal materials structures, using a scanning electron microscope (SEM). Prepared samples of seamless steel pipes were subjected to a thorough microscopic examination from the outer surface to the inner regions in order to interpret the spe-cific structure, including the change of the inner surfaces due to wear. The experiment showed that the micro-structure and character of the surfaces play a crucial role in the behavior of metallic materials under real condi-tions. Four types of pipes were monitored according to their use. The unused steel pipe (designated as sample No. 1) exhibited a rough outer surface with identified inclusions, while the used pipe (designated as sample No. 2) showed marks of intergranular corrosion and significant wear after long-term use. The older pipe (designated as sample No. 3) showed a decarburized area and inclusions containing sulfides and aluminum. The steel pipe with corrosion layers (designated as sample No. 4) exhibited a continuous corrosion layer with cavitation and cracks. The results of this study offer a comprehensive view relating to the influence of the nature of the micro-structure and wear on the water flow (performance) of metal pipes, with an emphasis on the identification of possible risks associated with geometry change, corrosion and wear. The recommendations create a basis for predicting the degradation as well as appropriate maintenance to ensure their long and reliable service life under real-world conditions of use.

The thesis deals with the surface treatments of bearing steel processed for wind turbines, on which the quality parameters of the surface treatments performed were compared. This is blackening, which is a method of surface treatment that allows the protection of the base material from the negative effects of external influences, in particular from moisture and associated corrosion. The application of surface treatment by blackening contributes to a better and more efficient start-up of the bearing in service. In the experimental part, the individual results of the structural analysis carried out for all types of materials investigated are evaluated, with the analysis focusing on the structural properties, the quality of the adhesion properties and the influence on the service life of the machine components. Electron microscopy was used to investigate the structural properties of the layer as well as the base material, which allowed to obtain the necessary data to meet the objectives of this work.

Wire electrical discharge machining (WEDM) was employed to process thin-walled, multidirectional carbon fiber-reinforced silicon carbide (Cf-SiC) composites. This study investigates the effects of key WEDM parameters, including gap voltage (Vg), pulse on-time (Ton), pulse off-time (Toff), and wire electrode type on material removal rate (MRR) and surface roughness (SR). All experimental planning, data analysis, optimization, and result visualization were conducted using MATLAB software. Results indicate that using CuZn50-coated wire electrodes increases MRR by 11% compared to CuZn37 bare brass wire. Scanning electron microscopy (SEM) confirmed the inverse thermal expansion-based material removal mechanism, revealing surface defects such as fiber fractures, interfacial detachment, craters, and micro-cracks. Surface roughness, as indicated by 3D topographic measurements was found acceptable with an average Ra between 2 and 3 μm. Overall, WEDM proves effective for machining Cf-SiC, especially for complex geometries such as holes, grooves, keyways, and splines when appropriate electrodes and parameters are applied.

The fuel content of engine oil is a significant factor affecting its degradation processes, lubricating properties and overall service life, especially in the case of modern internal combustion engines equipped with turbocharging, direct injection and exhaust gas recuperation systems. This study analyzes the dilution of engine oil with fuel in diesel and gasoline engines of vehicles with different degrees of wear, represented by the number of kilometers driven. The main objective of the research is to identify the relationship between the fuel concentration in the oil and changes in its physicochemical properties, as well as the potential impact of this phenomenon on the service life of the lubricant and the suitability of the set replacement intervals. The fuel content was quantified using precise quantitative spectrometric analysis, which allowed comparing engine oil samples taken under different operating conditions, including hot and cold starts, urban and highway operation. The results obtained show that vehicles with higher mileage and higher frequency of cold starts exhibit significantly higher rates of oil dilution by fuel, which directly affects the reduction of its viscosity and lubricating ability. The findings of this study provide important insights for the development of recommendations in the field of engine maintenance, especially with regard to optimizing engine oil change intervals, in order to prevent excessive wear and damage to engine components due to lubricant degradation.

Technology of adhesive bonding belongs to prospective bonding methods. The limit of adhesive bonds is cyclic loading which usually significantly decreases the service life of adhesive bonds and causes deformation of adhesive and cohesive bonds inside of adhesives. The article deals with the research of adhesive bonds exposed to cyclic loading. The aim of research was establishing an influence of the filler based on meshed coffee beans waste added into two-component epoxy matrix for bonding. The differences of mechanical properties of adhesive bonds with filler based on meshed coffee beans waste were evaluated at static and cyclic loading with 1000 cycles at first interval loading between 5 to 30% and second interval 5% to 70% of the static shear tensile strength.

A single-stage evaporator with natural circulation was used to densify the plasticizing bath through continuous evaporation and to prepare a solution used in the production of viscose fiber. During the process, sodium calcium sulfate salts were formed, leading to fouling of the heat transfer surfaces in the heat exchangers. This fouling created a layer of deposits that gradually reduced the efficiency of the evaporation process in the evaporator. It was determined that a processing medium with a volumetric flow rate of 6 m³·h⁻¹ required a heat exchanger power of 1448 kW. A fouling layer with a thickness of 0.1 mm reduced the heat exchanger's performance by approximately 40%. When the fouling layer increased to 0.5 mm, the heat exchanger power decreased by nearly 74%, down to 889 kW. The purpose of this paper was to analyze the process parameters of the densification technology in order to identify potential optimisations that could increase equipment availability and reliability. Alternatively, the study aimed to provide recommendations for design modifications to the existing technology.

A constant tension cable reel based on planetary gear transmission is introduced. The parameters of the mechanism are determined to analyze the speed and torque of the transfer mechanism. The relationship between the thread pitch and cable type show that different cable models require different parameters for the constant tension cable reel. The mechanism is designed to automatically adjust the force required for cable pulling and maintain a constant maximum tension. Then the relationship between the moment and speed of each output shaft is analyzed, and the operation mode of the cable reel was explained. The experimental results show that the proposed cable reel can pull the cable flexibly while providing the required constant tension, without damaging the cable and extending its service life. The pitch of the screw-thread pair is directly related to the required tension of the cable and the cable diameter. If the power supply cable model is different, the parameters of constant tension cable reel are also different.

This article deals with the comparison of the wear of indexable CNMG carbide inserts from two dif-ferent manufacturers when turning austenitic stainless steel 1.4404, which is not intended as the pri-mary material to be machined from the point of view of the tested inserts. The main goal was to demonstrate the different course of wear by testing inserts of the same type according to ISO 6987 showing the connection between the design and processing of the inserts in connection with the se-lected cutting parameters. The monitored type of wear was the main flank wear VBmax, depending on the length of the machining time. Optical and electron microscopes were used to analyze the flank wear. According to the assumption, it was found that the layout of the cutting edge geometry and coating layers has a noticeable effect on the degree of wear of the evaluated cutting inserts. At the same time, it was found that the tested indexable inserts achieved very good service life values de-spite the fact that the tested material does not belong to the primary use group. Evaluation of cutting tool wear has a significant economic potential for manufacturing companies seeking to minimize costs by trying to use as many universal cutting tools as possible or looking for opportunities to ex-pand the applications of already used cutting tools.

To increase the service life of the cutting tool, various types of coatings are used in modern times, which have a beneficial effect on extending the service life of the tools. Which contributes to reducing the eco-nomic costs of production. The present article examines the effect of cutting speed on the durability of a cutting tool. In the experimental measurements, three types of replaceable cutting inserts were used, without coating, with TiC and TiN coating. The measurements were carried out during technological operations of longitudinal turning on bearing steel 100CrMn6 without the use of coolant. The durability of the cutting discs was evaluated by the method of short-term tests, in which the main evaluation crite-rion was the amount of wear on the back surface of the cutting tool VBBcrit = 0.25 mm. For the statistical processing of the measured results, a detailed mathematical calculation was performed using the meth-od of least squares to determine the parameters of the linear regression function.

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.

The three-point front-mounted electric forklift is an important logistics tool nowadays. The wheel-side reducer is a vital power unit of the electric forklift. The cover plate of the reducer casing, as a key component, bears significant external loads. The cover plate of the casing is prone to deformation under the action of loads, leading to part scrapping and reducing the service life of the entire machine. Additionally, as the cover plate directly connects with the vehicle body, vibrations produced by the electric forklift during operation can affect the working stability of the reducer through the cover plate, reducing its lifespan. When designers design the wheel-side reducer cover plate, they first establish a 3D model of the cover plate using Pro/E. Then, the 3D model is imported into the finite element analysis software ANSYS. By integrating the Newton-Raphson iterative method, the cover plate undergoes static analysis, predicting potential design flaws and proposing corresponding optimization strategies. After several rounds of simulation and optimization, the cover plate meets the usage requirements. Through modal analysis, the inherent frequency of the cover plate is determined. This allows for the assessment of the relationship between the working frequency and inherent frequency, thus facilitating the improvement of the cover plate's design parameters to reduce resonance and noise. Through static and modal analysis, not only is the design cycle of the reducer cover plate shortened and production costs lowered, but resonance is also minimized, enhancing the working stability of the reducer.

In response to the need for trajectory correction during the excavation of curved tunnels by tunnel boring machines(TBM), as well as the impact of interference forces generated by the propulsion sys-tem on the design and service life of key components, as well as the low propulsion efficiency of TBM, a dynamic model of the propulsion mechanism during the excavation process is established, and the variation law of the angle between the key components of the thrust hydraulic cylinder and the gripper shoe hydraulic cylinder under the propulsion force of the hydraulic cylinder (1500KN) and three steer-ing angles of 0.5 °, 1 °, and 2 °, as well as the relationship between the gripper shoe hydraulic cyl-inder tightening force and horizontal propulsion force, has been studied. Research has shown that under the rated hydraulic cylinder propulsion force, during the process of increasing the swing angle of the main beam, the left angle and the tightening force on the left gripper shoe are less than the straight-line working condition, while the right side is greater than the straight-line working condition. However, during the forward excavation process after turning left, the X-direction propulsion force provided by the left thrust cylinder is greater than the X-direction propulsion force of the horizontal excavation, and the force on the left support shoe is less than the tightening force under the horizontal working condition, while the opposite is true for the right side. The research results have important theoretical significance for studying the optimal matching relationship between the mechanical model and excavation parameters of TBM during the propulsion process, as well as further improving the excavation efficiency and stability of TBM.

With the progress of science and technology and the continuous development of robot technology, the performance and intelligence of robots are also constantly improving. It has been widely used in many fields such as life service, military, industrial production and so on. Among them, autonomous mobile is an important embodiment of intelligence. Therefore, it is necessary to solve the problem of robot real-time positioning and map building (SLAM). SLAM is the abbreviation of Simultaneous localization and mapping, which means "synchronous localization and mapping". It is mainly used to solve the problem of localization and mapping when robots move in unknown environments. This paper designs and implements a positioning and navigation system for mobile robots based on lidar in the environment of robot operating system (ROS). The system is based on the gamping algorithm of particle filter, so that robots can perform self-positioning and map building in strange environments. By studying the Rao-Blackwelized particle filter algorithm and enlarging the bandwidth of Kalman filter to increase its estimation accuracy, the filter was optimized. In the process of robot implementation of map construction and autonomous obstacle avoidance, the robot can conduct self-positioning and map building in unfamiliar environments by using the algorithm provided by the open source Gampping function package in the robot operating system (ROS).The navigation function package allows the robot to navigate independently and avoid obstacles with known maps of the environment. Finally, the simulation tool gazebo of the robot operating system (ROS) is used to build the simulation environment required for the experiment and simulate the real environment of the robot. Finally, the robot is equipped with lidar sensors to carry out experimental simulation, so that it can achieve the functions of self-positioning, map building, self-navigation and obstacle avoidance.

Nickel-based superalloy is a kind of metal material that is widely used to manufacture high-temperature parts in the fields of aviation and aerospace, but it is also a typical difficult-to-machining material. The precision cutting of nickel-based superalloy has always been an important manufacturing problem. Based on the tests of conventional drilling with three kinds of twist drills, the machinability of Inconel 718 was evaluated comprehensively by drilling force, tool wear and machining quality, and the cutting tools suitable for drilling nickel-based superalloy were chosen. Then the experiments of peck-drilling for Inconel 718 were carried out, and the process effect under different peck depth Q was deeply researched. The results showed that the HSS-Co (high speed steel with cobalt) twist drill can meet the needs of low-speed drilling of nickel-based superalloy, while the coated carbide twist drill has better service performance. The drill tip structure of dual clearance angle is beneficial to decrease the cutting friction and improve the machining accuracy. Compared with conventional drilling, the peck-drilling can reduce the cutting force and improve the dimensional accuracy and surface quality. However, it is very important to choose a suitable peck depth Q for fully exploiting the advantages of peck-drilling.

The article deals with the possibility of increasing mechanical and utility properties by means of regenerative heat treatment. Experimental program is focused on the heat treatment of low-alloy heat-resistant steel EN ISO 14MoV6-3. This steel has been used since the 1970s for high-temperature exposed components in practically all coal-fired thermal power plants in the Czech Republic. Thus, steel EN ISO 14MoV6-3 is currently the best studied refractory material whose data, collected from experimental creep behaviour tests, exceeds the computational service time 2.105 hours. In order to remain competitive in the new energy mix, conventional steam power plants are forced to adapt to the requirements of semi-scheduled power generation. However, these plants were not originally designed for such operation and therefore have to adapt to new demands on the timing of the power provided, including requirements to reduce overall plant emissions and to increase the efficiency of power generation. These components are now subjected to substantially increased cyclic stresses due to power changes during half-cap operation. These stresses have a major impact on the material lifetime and therefore on the overall performance and lifetime of the plant.

Titanium and its alloys are an important structural material in all sectors of industry. Thanks to its mechanical properties. One of the most widely used titanium alloys is the Ti6Al4V alloy. If we heat alloys for a long time in an air atmosphere, TiO2 is formed on the surface of the parts. The Ti6Al4V alloy, also referred to as Ti64, is a two-phase alloy formed by α+β solid solutions from the point of view of microstructure, it is characterized by corrosion resistance and good biocompatibility. Through heat treatment, we can improve the mechanical properties of the alloy, improve the fracture toughness, influence and reduce the internal stress and influence the machinability of the material. To achieve a longer service life of products made of this alloy, we can use the method of surface treatment, in the form of nano layers. An analysis of the Ti6Al4V alloy was performed for the cell, after heat treatment at temperatures of 650 °C and 800 °C and followed by corrosion loading in a salt fog environment. The exposure time in the corrosive environment was between 168 and 720 hours. Changes in the microstructure were ob-served and the change in microhardness in the surface layers of Ti6Al4V was described.

With the development of welding technology and the improvement of automation level, welding robots are playing an increasingly important role in industrial production. However, during the welding process, due to factors such as material characteristics, welding parameters, or improper processes, defects may appear on the surface of the workpiece, which may reduce the quality and service life of the workpiece. In order to solve this problem, this article used frequency domain feature extraction and nearest neighbor classifier in workpiece detection algorithms under machine vision technology to extract and classify surface defect images of workpiece, and studied the detection method of welding robot workpiece surface defects. The research results indicated that, under the same other conditions, the accuracy of machine vision technology was over 90% for all five different defect types, while the accuracy of traditional technology was between 75.5% and 84%. The performance of machine vision technology was far superior to traditional technology, indicating that machine vision technology could improve the accuracy of welding robot workpiece surface defect detection methods.

A modern user requires low operating costs, but also reliability from machines and technical devices. Reliability during the service life depends on the quality of construction solutions, but also largely on the quality, properties and adaptation to the working conditions used in the construction of construction materials. During the operation of technical objects, their a highly predictable wear occurs. The problem is the phenomena of premature wear and damage of elements. The causes of failure of technical facilities are usually complex and depend on many factors. They can include the human factor and the one related to the quality, selection, production and technological processes of the materials used in the construc-tion of the facility. In real technical facilities, many premature failures are caused by material fatigue, which is related to the quality and distribution of impurities in the material. The paper presents the change in fatigue strength for rotational bending of low-carbon structural steel hardened and tempered at different temperatures as the effect of the size and distance between impurities on the fatigue strength of high-quality carbon structural steel melted in the industrial conditions in an electric arc furnace.

This article is dedicated to exploring the potential enhancement of mechanical properties, such as hardness and tensile strength, in selected Al-Si alloys (AlSi7Mg0.3, AlSi7Cu4, and Al-Si10.5Cu1.2Mn0.8Ni1.2). High-melting-point elements, such as chromium and molybdenum, are rarely utilized as additives in Al-Si alloys. However, the article demonstrates the feasibility of improving the mechanical properties of these alloys through the addition of high-melting-point elements. High-melting-point metals, often referred to as refractory metals, typically have melting points above 2000 degrees Celsius. Common refractory metals include tungsten, molybdenum, tantalum, niobium, rhenium, and others. These metals exhibit excellent mechanical properties at elevated temperatures and often possess high density and good corrosion resistance. All casts were made using by gravity casting with different heat treatment conditions at 740 °C. The microstructures, hardness, microhard-ness and tensile strenght of the samples were analyzed. Hardness measurements were conducted using two types of hardness testers according to ČSN EN ISO 6506-1 for the Brinell hardness test method and ČSN EN ISO 6507-1 for the Vickers hardness test method. A static tensile test was performed on a universal testing machine, Inspekt 100, in accordance with the standard ČSN EN ISO 6892-1. The measured data demonstrated that high-melting-point metals affect each alloy differently. In some alloys, mechanical properties improved after heat treatment, while in others, a significant deterioration was observed, particularly in tensile strength.

The cutting performance of abrasive water jet (AWJ) machining is commonly evaluated using cutting depth, cutting efficiency, and specific cutting energy. To systematically investigate the influence of process parameters on AWJ cutting performance, a five-axis CNC cutting platform was developed, allowing precise control of operating conditions. Single-factor experiments were conducted to analyze the effects of pump pressure, traverse speed, cutting angle, abrasive mass flow rate, standoff distance, and nozzle diameter. Both qualitative analysis and quantitative evaluation were employed to identify parameter ranges that maximize cutting efficiency or minimize specific cutting energy. The results indicate that the minimum specific cutting energy is achieved when the pump pressure is approximately three times the threshold pressure, the traverse speed is 110 mm/min, the cutting angle is 90°, and the abrasive mass flow rate approaches its optimal value. The effects of standoff distance and nozzle diameter on specific energy depend on their combined influence on cutting depth and kerf width. In addition, repeated cutting passes were found to increase energy consumption, indicating that complete material penetration in a single pass is more energy-efficient. These findings provide practical guidance and theoretical support for achieving high-efficiency and energy-saving AWJ cutting processes.

To address cracking and deformation in large-size ceramic slabs during firing induced by thermo-structural coupling, this study established an indirect thermo-structural coupling finite element model in Ansys to analyze an 820 mm×100 mm×6.32 mm slab. The evolution of temperature field, stress field, and deformation was investigated across four firing stages. Results indicate that the rapid cooling stage, with a high convective heat transfer coefficient, forms the cycle’s maximum thermal gradient, showing the most asymmetric temperature field of mid-plane high, surfaces low and a ~17°C surface-mid-plane temperature difference. The stress field follows a low-high-declining-stable trend, peaking in rapid cooling of 23 MPa maximum equivalent stress in the thickness section and 11 MPa maximum principal stress at the glaze-body interface. Thermal gradient, glaze-body CTE mismatch, and boundary constraints respectively drive stress generation, interface concentration, and asymmetric distribution. Deformation obeys length > width > thickness in rapid cooling, lengthwise deformation is 8.2 times the width. Thickness-direction drum-shaped deformation stems from glaze-body CTE mismatch. This study reveals the firing thermo-structural coupling mechanism, providing theoretical support for optimizing firing processes and glaze-body formulations, with significant engineering value for reducing cracking and improving dimensional stability.

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.

The use of supercritical water in energy applications is motivated by the aim of increasing the thermal efficiency of power systems. However, structural materials exposed to this environment may undergo corrosive degradation. The objective of this study was to conduct experiments on samples exposed to simulated operational conditions in supercritical water, steam, and air. The material surfaces were sub-sequently analyzed using optical microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM/EDS). Particular attention was given to the formation of oxide layers on the nickel-based alloy Inconel 718 produced by additive manufacturing by PBF-SLM technology. The corrosion behavior was evaluated by monitoring mass gains. The results were compared with materials manufactured using conventional techniques.