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The 54SiCr6 high-strength low-alloyed steel with medium carbon content is studied in this work. Its excellent mechanical properties allow a wide range of applications as springs and vibration dampers. The high strength is usually achieved during heat treatment consisting of quenching and tempering. This manuscript represents several methods to further increase in mechanical properties. Firstly, the influence of microstructure before quenching and tempering was studied and enhanced plastic prop-erties were measured. Secondly, a thermomechanical treatment before quenching increased the strength. Finally, the use of strain assisted tempering caused a further strengthening effect compared to conventional tempering. All these methods improve mechanical properties, some increase strength and others ductility.

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.

New energy vehicles driven by electric motors have higher requirements for the lightweight and high reliability of their gear transmission devices. It is now necessary to optimize the precision forming process of their structural gears. The integrated structure gear without undercut produced by precision forming technology can reduce axial size while improving the strength and reliability of gear parts. Based on the performance requirements of integrated structural gear parts in practical applications, a process plan of "hot forging forming +cold trimming tooth shape" was developed, and compared with existing hot extrusion forming plans. Simulation analysis was conducted on the hot forging forming process of integrated structural gears. Through the improvement and optimization of the process plan, the extrusion stress during the filling process of the formed gear teeth was reduced by about 29%, achieving a good forming effect, in order to provide data reference for the forming of this type of gear.

Measurement results on the Damping Loss Factor (DLF) and Coupling Loss Factor (CLF) between two steel plates is presented for 19 different junction types. The junctions involve joining technologies as line welding, point welding, bolting, riveting, gluing or their combinations, with parameters, such as spac-ing between the junction points or the angle between the plates varying. From the measurement results the DLF and CLF values were calculated by the Power Injection Method for the purposes of being ap-plied in Statistical Energy Analysis simulations. Four excitations were applied at each subsystem by impact hammer, while the response was recorded at sixteen response points at each subsystem. The measured CLF values were compared to each other from various aspects. Data were compared to the results obtained from SEA simulations by using the built-in analytical formulas. In general, good com-parison was observed, although the results appeared to be somewhat dependent on the frequency band. Finally, it was examined whether replacing the DLF values with data obtained for an uncoupled flat plate as well the CLF values with data from analytical formulas leads to acceptable accuracy of the re-sults.

This paper presents a new method of improving the material removal process in metal cutting. Chip formation plays an important factor in the metal cutting process and increasing its condition has a great impact on cutting machine details. Based on lubricating cooling conditions in the metal cutting process, a novel methodology is proposed to decrease the deformation that emerged in the material removal process while cutting cylindrical details in lathes. Application of stating magnetic field on flowing cutting fluids decreased the shrinkage of the chip in turning operation. Analytical and practical experiments show that the effect of cutting fluid under the influence of a static magnetic field decreased the shrinkage of the chip up to 20 % in comparison to the conventional use of cutting fluids in turning cylindrical pars with HSS tools.

SLS additive technology is an innovative method of metal components production, using a high material proportion. Currently, gearwheels are still one of the most used engineering parts, not only in the automotive, but also in other industries. For example, milling is used to reduce their weight, but the material can be distorted after this operation. The occurrence of cracks propagating in the transition region after induction hardening was the reason for conducting experiments with an alternative machining technology. The article deals with the identification of the influence of machining on residual stress change of a gearwheel made of sintered metal powder. The research focuses on the effect of boring on the residual stresses using a non-destructive measurement method using röntgene diffractometry.

Article presents a novel approach to addressing the challenge of forge-free filling of gas cylinder valve knobs in the context of the pneumatic shock absorber utilized within elevator systems. The shock absorber is a critical component responsible for ensuring accurate and efficient transportation of charge material to the electric inductor of automatic hot forging presses. Precise control of the shock absorber's operation is essential for maintaining proper system functionality and minimizing deficiencies. To investigate the system's response to changes in shock absorber operating parameters, the authors conducted a comprehensive simulation. The simulation results revealed that by identifying specific and optimal operational characteristics, the level of deficiencies can be significantly reduced. These findings offer valuable insights into system behavior, facilitating the optimization of shock absorber operation and overall improvement of the hot forging process. Implementation of the optimized shock absorber operation based on the simulation outcomes can enhance productivity, cost-efficiency, and quality in the hot forging industry.

The main objective of the work was to describe the laboratory methods suitable for hydrogenation of free-cutting steels and to study the hydrogen embrittlement of 11SMn30 free-cutting steel. Hydrogenation and subsequent mechanical testing of hydrogenated steel is not common laboratory method as it requires precise and expensive equipment, is time consuming and dangerous as hydrogen is highly reactive and explosive. Currently, there are several theories of hydrogen embrittlement mechanisms of steels that describe the causes of material degradation by hydrogen. However, those theories are not universally valid; individual accounts have been developed and describe hydrogen embrittlement only for specific conditions and may fail in their descriptions under others. In this work, the hydrogenation of free-cutting steel 11SMn30 steel by two different methods (immersion and ca-thodic) was investigated in order to induce embrittlement and to compare in particular the fracture surfaces after the Charpy impact test. The results reported in this paper indicate that manganese sulphide inclusions are not the main cause for hydrogen embrittlement in free-cutting steels. The effect of manganese sulphide inclusions was attributed only to hydrogen trapping, that generated a high stress causing their decohesion from the matrix.

Atomic Diffusion Additive Manufacturing (ADAM) is a recent metal sintering process based on known composite printing technology. ADAM can be classified as indirect additive production using fibre of metal powder bound in a plastic matrix. The plastic binder allows the metal powder to remain in place when is printing. Thus, a "green part" is printed and then the plastic binder is removed by the post-washing and sintering process. The aim of this work is providing a brief description of the ADAM process patented by Markforged. Furthermore, the main task was to compare the technology with other sintering technology, namely SLM technology. It works on the basis of selective bonding of metal powder using the thermal energy of the laser beam. Parameters, such as dimensional and shape accuracy, roughness of printed surfaces or tensile strength of printed samples were examined and compared. Dimensional accuracy of the ADAM process was evaluated using ISO IT grades - determined on the basis of the reference standard. The observed accuracy of the sintering process was comparable to traditional production processes.

An experimental study was carried out on the effect of oxidation temperature and the oxide film composition on the compressibility of porous materials. samples were annealed at different temperatures; the size change in the samples after annealing was measured. The phase composition of the oxide layer was investigated. Magnetite was generated at between 350 and 450°C, and two-phase oxide was formed at 550°C, after oxidation, weight gain was determined. The presence of pore overgrowth, which reduces porosity, was confirmed by metallographic tests. The maximum porosity is found in the oxidized samples produced by pressing at room temperature. The process of high-temperature oxidation of iron powder before pressing and in the state of free filling in a fluidized bed, as well as the effect of the content of oxides on magnetic characteristics, has been studied. The impact of oxidation on the compressibility of samples of iron powder was investigated. In this study, It was observed that the range of 350-450°C, which offers the best compressibility and the necessary composition of the oxide film, is also related to the presence of magnetite in the iron oxide coating. is the ideal temperature for oxidation and repressing. the deformation of porous materials exposed to iron powder oxidation was tested.

Aluminum alloys are one of the most used materials today, and therefore great emphasis is placed on their continuous development. Improving the ratio of strength and stiffness to weight, improving plasticity, casting properties or resistance to corrosion are examples of properties of aluminum alloys that are constantly being improved. This work focuses on the evaluation of the corrosion resistance of the Al-Si5Cu2Mg alloy with graded addition of zirconium (0.05; 0.10; 0.15; 0.20 wt.%). Corrosion re-sistance was evaluated based on immersion, exposure and potentiodynamic polarization tests. The addition of Zr to the AlSi5Cu2Mg alloy improved the thermodynamic stability in all evaluations. The application of heat treatment led to even more significant increases in corrosion resistance in almost all evaluations. Microscopic observation of the samples revealed mainly pitting corrosion along with intercrystalline corrosion.

This research focuses on comparing the working accuracy of two additive manufacturing processes, Atomic Diffusion Additive Manufacturing (ADAM) and Binder Jetting (BJ). Through the analysis of key characteristics of these processes, we aim to evaluate which one yields better results in terms of working accuracy. ADAM is a process that involves the gradual deposition of metallic materials using a plastic binder, whereas BJ is a process where the binder is applied to powder material, followed by the removal of excess binder. This work conducts a detailed examination of the properties of the ADAM and BJ processes, with a focus on surface texture and microstructure of the resulting objects, the use of optimal technological parameters, and the assessment of dimensional and shape accuracy. It is also important to note that the final nature of 3D objects depends on technological parameters such as geometry, orientation, and placement of individual shape specifications. The results of this study are crucial for assessing the accuracy of these additive processes and can serve as a significant basis for selecting an optimal approach in the field of additive manufacturing.

There is a lot of applications for manipulating industrial robots nowadays. Maximizing the tasks that can be assigned to robot manipulators is one of the criteria for deciding if their application is appropri-ate. The article discusses the topology optimization of the gripping jaws of an industrial robot to reduce the jaws' weight. The previously used gripping element made of C50E steel was optimized to reduce the weight of the jaws. Shape optimization was performed based on analysis from CAD programs Inventor Professional 2022, Autodesk Fusion 360, and Ansys Discovery. The new jaws were manufactured by the additive technology of selective laser sintering (SLS) from PA12 material. The optimization resulted in a significant reduction in weight compared to the original jaws. As a result of optimizing the weight of the designed jaws, it was possible to increase the weight of the object of manipulation.

The paper presents the possibilities of using the wavelet transform to filter the cutting force signal. Tests were carried out by dry turning on the Ti6Al4V alloy with variable cutting parameters. Four blades with different nose geometry and coatings were used. From the recorded waveforms, the mean values of the force component Fc and the load stability coefficient were calculated. The measured force waveforms were filtered with Daubechies 4 (db4) and Daubechies 6 (db6) wavelets. From the ratio of the load stabil-ity after filtration to the load stability before filtration, the noise and disturbance values generated during the turning of the tested alloy and the force measurement were estimated. The conducted research shows how the machining conditions affect the values of force, stability, and thus also the variability of the cutting edge load when turning a titanium alloy. They also show the effectiveness of the Discrete Wave-let Transform (DWT) in separating the noise from the force signal.

Welding techniques such as gas tungsten arc welding (GTAW) can induce solidification cracking owing to the wide solidification temperature range. Riveting or mechanical fastening are plausible alternatives, but can create problems like material loss, overall weight increase, corrosion, and introduction of high stress concentration areas. This study proposes a new welding method to improve and minimize centerline solidification cracking in GTAW called “tandem side-by-side GTAW welds”. AA2024 is fusion welded using GTAW, and its solidification cracking behavior is investigated and compared for two weld pool motions (straight and weaving) and the proposed method. The fishbone test was used to assess centerline solidification cracking susceptibility. The results of welding AA2024 autogenously proved that the tandem weld pool motion is superior to the other two GTAW methods. As a result, the proposed method showed lower stress concentration areas by forming less concave weld shapes, lower heat input, formation of preferable grain size and orientation thus shorter centerline solidification crack lengths with a tortuous crack path motion obtained in comparison with the straight and weave.

This article deals with nanoindentation analysis of welded overlay layer of Inconel 625 alloy on 16Mo3 steel and their interface (transition zone). The microstructure of weld metal is analyzed, as well as the weld-on steel and subsequently nanoindentation properties (nanohardnes, reduced modulus of elastic-ity) of selected structural components. The weld of Inconel 625 alloy is realized on a tube made of 16Mo3 steel, which is bent by the so-called critical bending (d≤0,7D). The article also deals with the change of investigated properties of the weld after that bending. The samples prepared from the areas with highest compressive and tensile load after the tube bending on outer, respectively inner bend arc were used for the research. Nanoindentation analysis was performed with using a Hysitron Triboin-denter TI950 and its evaluation software Triboscan.

The condition for the designability and efficiency of the machining processes is that the part production process is chosen to meet the operational requirements based on the most accurate technological plans possible. One part of this is the planning of the required quality and roughness of the surfaces and achievement of the required values in the finishing. In this paper, a study on the predictability of surface roughness was performed using a CAD model based on theoretical roughness and validated by cutting experiments. The reported results show the effect of the feed rate change in face milling for two tools with different edge geometries in planes parallel to the feed direction.

The work deals with the possibility of using additive technology in the production of positioning and clamping device. The designed clamping device will facilitate and accelerate the measurement of samples with inclined or different irregular surfaces. The designed device is manufactured by additive technology using composites. Onyx material reinforced with Kevlar fibers was used as material for composite printing. The designed device should achieve the required properties for the firm and stable clamping of the components during the measurement process, and its weight should be significantly reduced with the use of composite material.

In vibration-assisted drilling, the wear state of the drill bit affects the processing quality of the hole. The traditional method of identifying the wear state of the drill bit adopts the method of packet de-composition, ignoring the timing characteristics of the signal. In this paper, the force and acoustic emission signals in vibration-assisted drilling are used. The Gram angle field converts the one-dimensional time series into a two-dimensional image, while retaining the trajectory of the time se-ries in the high-dimensional space. Based on the Graham difference field (GADF) image of force and AE, the Inception improved convolutional neural network (IN-CNN) is used to identify the wear state. The experiment proves that compared with the traditional convolutional neural network, BP neural network and support vector machine, the recognition rate of IN-CNN drill wear state based on GADF is 93.1 %, which is increased by 2.5 %, 10.6 % and 8.1 % respectively. It provides a reliable condition monitoring method for the state identification of the drill bit in semi-closed vibration-assisted machining, and has practical engineering significance for improving the machining accuracy and efficiency of composite equal-holes.

The subject of research is the kinematic parameters of a biplanetary mechanism of the intermitted mixing machines. The article substantiates analytical expressions for determining the kinematic parameters of the drives of the working body of the intermitted mixing machines with planetary ones with double satellites and biplanetary mechanisms; the laws of change of displacements, velocities and accelerations of the points of the working body for drives with planetary one with double satellites and biplanetary mechanisms are determined; the regularities of the influence of the velocity parameters of the driving links on the kinematic characteristics of these mechanisms are established.

This study focuses on the analysis and solution of thread production in thin-walled profiles. It explores three different threading technologies, including cutting, forming, and extrusion. The issue of a screw joint in a thin-walled component is complex due to the stiffness of the joint and the short length of the thread. Hence, the careful choice of a suitable manufacturing process for producing inner threads in thin-walled components holds significant importance. The study entails monitoring the hardening of surface layers of materials after thread production, in conjunction with the acquisition of microstructure images of the experimental material. The outcome is a comparative evaluation of different individual thread production technologies.

Parts made by 3D printing must be subjected to heat treatment to achieve the required mechanical properties. With the development of additive manufacturing in various areas of industry, more and more complex components are being printed, which, in addition to their complicated shape, also have different printing heights. Sometimes, builds of different heights are created on a single build platform. When there is a height difference, the step region is characterized by a steep increase in hard-ness. It may lead to problems related to mechanical properties. MS1 tool steel was chosen as the material for this experiment. Using DMLS (Direct Metal Laser Sintering), a build with considerably greater height was created on the build platform together with other parts. Metallographic examination of the printed part was carried out and its hardness profiles were measured prior to as well as after heat treatment. The drop in hardness in the build of different height was up to 40 HV10. Solution annealing at 820°C removed the transition produced by building a single part, both in terms of microstructure and mechanical properties.

This paper focuses on the issues of tool thermal deformation during machine preheating，designing an image-processing-based solution for measuring these tool thermal deformation, to obtain the axial thermal error of the tool as a function of preheating time.This paper uses a high-speed camera to collect images of tool thermal deformation. Using MATLAB software, rough localization of images by Canny algorithm for edge extraction. Accurately locating tool edge outlines using a sub-pixel fitted edge detection method, that is, using the least squares method to fit a tool tip arc curve. From this, the thermal deformation during tool preheating is calculated. This study will serve as a basis for the compensation of thermal errors in machine tools.

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.

The paper describes the effect of laser traverse speed during laser hardening on hardness and micro-structure. The experimental material is hot work tool steel AISI H11 with samples sized 100×100×35 mm. The initial state of the material before laser hardening is quenched and tempered. The laser hardening temperature is constant at 1100 °C, selected laser traverse speed was 1, 2, 4, and 6 mm/s. A numerical simulation performed in DEFORM-3D software before the experiment showed tendencies of temperature displacement and expected course of hardness. Increasing traverse speed leads to de-creased laser-hardened depth and decreased hardness drop in the heat-affected zone (HAZ). The ex-perimental program confirmed the results of the numerical model. The differences in the microstruc-ture were investigated by light (LM) and scanning electron microscopes (SEM), which revealed an evident difference between the surface area and the locality with the lowest hardness. Local differ-ences from the perspective of presence of carbides were analysed by energy dispersive spectroscopy (EDS). This investigation was performed to optimize laser traverse speed to improve the subsurface hardness profile, which is essential for the lifetime and reliability of forging dies.

To be competitive, present-day manufacturing industries strive to optimize manufacturing parameters and produce quality products consistently. From various manufacturing processes, welding is one of the key processes for joining a large variety of indispensable products including the production of automotive body in white structures, assembly of large metal civil structures, nuclear installations, pressure vessels, aircraft, and spacecraft materials, etc. In order to get the level of quality requirement of welded components, an optimized combination of welding parameters plays a vital role. However, the realizations of this optimum combination of welding parameters for all processes in different conditions are the big challenge for the manufacturing industry. The current study presents a critical assessment of the various researches in the fields of gas metal arc welding of steel to create a descriptive picture of the effect of input parameters on weld quality characteristics. To realize this, intensive literature reviews and comparisons of different results have been made, and findings have been incorporated. Where there are differences in trends of parameter effects, proper explanations and justifications have been drawn. As a result, it was found that arc voltage, welding current, wire feed rate, and travel speed affect the quality of the weld (mainly penetration, bead height, bead width, and heat affected zone) significantly compared with other parameters considered in the context of this paper. This shows that the proper setting of the optimum combination of welding parameters specifically, arc voltage, welding current, wire feed rate, and travel speed yield the desired quality level of the weldment.

A considerable attention is paid to the production and monitoring of the properties of metallic cellular structures and the properties of aluminium foams, respectivly. Foam structures can be manufactured in three basic ways (by blowing the external gas into the melt, by melt gasification due to the thermal decomposition of the foaming agent, by the melting of the foamable preform which contains foaming agent particles). The paper addresses to our publication [18] and furthermore focuses on the investigation of mechanical properties of two types of foamed AlSi12 aluminium alloy samples. Samples (150x25x10 mm) were produced by powder metallurgy using a foaming agent TiH2. The characteristics features of the produced foam structures (relative density, porosity, volume fraction of solids, Young's modulus of elasticity) were studied on AlSi12 alloy samples. In addition, the porosity of samples and continuity of their air cells were monitored usign the scanning electron microscope.

Fused Deposition Modeling (FDM) is one of the widely used technologies of additive manufacturing. The concern over the surface quality and dimensional accuracy is getting increased among the research community. The design of the experimental methodology is based on the analysis of variance (ANOVA) of fractional factorial design. This analysis was used to study the effect of layer thickness, extrusion temperature, speed of deposition, and fill density on dimensional accuracy and surface roughness of the model developed by FDM. Polylactic Acid (PLA) material has been selected in this work as it is inexpensive, easy to print, and biodegradable. The results showed that layer thickness is an effective factor in determining surface roughness. Fill density (X and Z dimensions), layer thickness (Y dimension), and speed of deposition (Z dimension) are significant factors for dimensional accuracy. Regarding surface roughness, curvature was found to be significant; however, the minimum optimization point was not reached. Thus, more experiments are required to be carried out to get the minimum point. For dimensional accuracy optimization, the dimensions along X, Y, and Z were realized to be more accurate at lower levels of every factor except for fill density (D), which was optimized

In order to quickly measure the straightness parameters of the deep hole/blind hole axis, a robot for measuring the straightness of the deep hole/blind hole axis based on the photoelectric prin-ciple is designed. Using the linearity of the laser as a reference, the straightness of the inner hole can be detected through the function that the PSD sensor can accurately locate the position of the energy center of the light. By studying the relationship between the position of the light spot and the output voltage of the PSD device, the measurement model of the straightness of the deep hole axis is derived. During the measurement, the robot spiral driving mechanism moves back and forth inside the deep/blind hole, and the automatic centering mechanism realizes the precise positioning of the deep/blind hole axis. The laser fixed on the axis of the automatic centering mechanism can illuminate the PSD target to obtain the current position data of the deep/blind hole axis. Use the least square median method to eliminate the gross error of the obtained data, and the least square principle fitting can obtain the measurement results of the current axis straightness. In order to ensure the measurement accuracy, the measuring robot is calibrated by a standard ring gauge and used for the age of the pipe with an inner diameter of 135mm to obtain an error accuracy of less than 0.05 mm for the axis.

Even today, there is an ever-increasing demand for the production of aerosol cans made of aluminium, as the cosmetics and other propellant-enriched products stored in them reach more and more people with the development of humanity. The production of these packaging materials is primarily carried out by plastic forming operations. However, during the production process of aluminium aerosol cans, tools with a defined edge geometry also perform cutting operations. The processes taking place here affect the quality of the final product. In this paper, the procedure and results of finite element modelling of the flange turning of aluminium aerosol cans is presented. The structure of the finite element model is introduced, as well as the possibilities of considering the peculiarities of the process. Since the used pure aluminium (Al99.5) is considered a difficult-to-cut material, the machinability of aluminium and its alloys is also discussed.