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Based on the previous research on the 304 stainless steel lapping and polishing in our research group, the tribochemical fixed-abrasive lapping platen for 304 stainless steel lapping and polishing were developed. The effects of the different pressure, the rotation speed, the lapping time and the abrasive size on the surface roughness and the material removal rate (MRR) were researched. It was concluded that when the abrasive size is 28 µm, the lapping time is 15 min, the lapping speed is 90r/min, the lapping pressure is 27.580 KPa, and the maximum MRR is 412.524 nm/min. When the lapping time is 15 minutes, the rotating speed is 15 r/min, the lapping pressure is 13.790 KPa, the surface roughness Ra drops to 41nm. These findings show that the influence degree on the MRR from better to worse is the abrasive size, the lapping pressure, the rotation speed of the lapping platen and the lapping time. The order of the influence degree on the surface roughness from better to worse is the abrasive size, the rotation speed of the lapping platen, the lapping pressure and the lapping time. The results can give an important reference for next study on the tribochemical mechanical lapping of fixed-abrasive.

The continuous development of construction due to the great needs of society and industry, the need to build newer and more durable buildings have meant that scientists all the time look for new opportunities to improve the quality of materials used in this field. Above all, concrete, as material commonly used in construction, has been the subject of research for many years in order to improve the properties. Already in antiquity there were the first attempts to modify the building material with fibers. Initially, they were organic fibers. However, the first patent dates from 1874, when A. Bernard patented the idea of strengthening concrete with steel filings [1]. Then, attempts were made to strengthen the concrete with long steel fibers, which was done by H. Alfsen in 1918. Further researches led N. Zitkiewic to test the strength and impact toughness of concrete with the use of pieces of mild steel wire [2]. Steel fibers in concrete were used for the first time by Romuladi and Baston in 1963. In the paper a comparative analysis of selected mechanical properties for concrete and fiber-reinforced concrete, e.g. compressive strength and Young's modulus, was presented. It was checked how the value of Young's modulus and the compressive strength of concrete change depending on the content of steel fibers. Three types of samples were tested: 1 - concrete, 2 – fiber-reinforced concrete containing 0.25% of steel fibers, 3 – fiber-reinforced concrete containing 0.50% of steel fibers. As the analysis has shown, the greater number of steel fibers is not directly proportional to the increase in its compressive strength or the value of Young's modulus.

The changes in the material properties of water turbine blades are characterized an undesirable process, which could lead to the end of usable life or to the emergency conditions of this turbine. For this reason, it is important to determine of any material quality changes and continuously monitor them. Considering that, these essential parameters are showing the ability of material to resist the operational stress. It is necessary to choose rapid methods of the material testing which are without preparation of the samples (it is inadmissible to the functional blades) able to immediately monitor the state of the materials by non-destructive methods. Due to mechanical stress and operational wear, the losses and damage occur in the water turbine blades, as the result, it leads to the deformation changes. This article is focused on the methodology of determination mechanical properties of corrosion-resistant steel, which is used on a large scale for the production of hydraulic elements and especially blades of water turbines.

Titanium alloys are among the biocompatible materials that are used for biomedical implants. From the point of view of the reactivity of the human body, it is important to know the state of the surface of these materials, which in technical practice is represented by the term surface integrity, which includes a complex of evaluated properties. One of the classic approaches is the evaluation of the surface roughness and the properties of the stable oxide layer, which influence the formation of the connection of the implant with human tissues and influence its acceptance. Another frequent approach is the use of optical metallography, especially for the assessment of material thickness, distribution and character of corrosion attack. Less common is the use of electron microscopy in the evaluation of the surface, which in this case is affected by the action of corrosion. Samples of both pure titanium and Ti6Al4V alloy were divided into sets according to surface roughness and subsequently exposed to corrosion for different periods of time. The presented article is devoted to basic analyzes of the effect of roughness on corrosion behavior using not only classical optical but also electron microscopy.

The basic process of acquiring new knowledge is trial/experiment. We can define an experiment as a certain process that we prepare, organize and plan in order to know the object under investigation. Each experiment requires a multifaceted activity associated with professional knowledge, preparation of material security, espe-cially security with measuring devices and measurement methods for determining the correct (objective) measured values. Planning experiments and analyzing the obtained results are important stages in revealing the nature and course of the technological process. With the planned experiment, we try to create such con-ditions that the range of experiments is as small as possible, but the volume and form of information are of the highest quality. The article presents the method of the planned experiment and its use in industrial prac-tice. The mentioned methodology of the planned experiment is applied to the calculation of the mean arith-metic value of the surface roughness Ra depending on the cutting parameters. The advantage of this method is that it increases the accuracy of the obtained results, but mainly reduces the number of performed at-tempts.

The development of metal structural materials with low density, high specific strength and large internal friction is extremely urgent for the development of lightweight, high speed and high power of equipment and railway. The properties, microstructure and the evolution of interfacial bonding of composite materials are closely related. In this paper, the microstructure of Ti2AlC/Mg matrix composites with double-scale three-dimensional network is mainly studied. The prepared composite material presents a three-dimensional network in macro-micro scale, and the matrix and reinforcement are connected with each other. The mechanical properties and damping properties of the prepared dual-scale three-dimensional network Ti2AlC/Mg matrix composites and magnesium alloy matrix were tested. At the same time, the equivalent modulus of three-dimensional network Ti2AlC/Mg matrix composites on microscopic scale is predicted by finite element method according to the basic properties of Ti2AlC ceramics and AZ91D. The following conclusions are drawn: the ultimate bending strength of the composite material is increased by about 10% compared with its matrix magnesium alloy, and its ability to maintain strength is greatly improved compared with the matrix. Using the extracted information, the equivalent modulus of the composite microscopic model is calculated to be 31.25734 GPa, which is consistent with the experimental results. It provides data and theoretical support for similar research.

The presented article focuses on the surface analysis of the components manufactured by different additive technologies and their reverse digitization. Sintered components were manufactured by SLM and ADAM technologies, while their surface was analyzed using a progressive optical measurement method. To examine the possibility of reverse engineering, the components were optically scanned with a laser scanner and compared to their CAD model. Based on empirical experience, to scan opti-cally the metal and lustrous surfaces is a challenge. The components were manufactured from anti-corrosion materials 17-4 PH and 316L–0407.

Nowadays, a lot of data is generated in production and also in the domain of assembly, from which different patterns can be extracted using machine learning methods with the support of data mining. With the help of the revealed patterns, the assembly operations and processes can be further opti-mized, thus the profit achieved can be increased. This article attempts to explore the patterns related to the most used Key Performance Indicator (KPI) in manufacturing, the Overall Equipment Effec-tiveness (OEE) metric. The patterns and relationships discovered will be sorted into Assembly Pattern Catalogue (APC). Firstly, a literature review demonstrates scientific relevance. Secondly, it examines the circumstances and methods of samples in the Manufacturing Execution System (MES) data source and Enterprise Resource Planning (ERP) systems. In the third section, the detailed pattern catalogue is defined in the area of assembly. The novelty of the article is that beyond the generaliza-tion of patterns, it characterizes the pattern catalogue with mentioning practical industrial examples.

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.

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.

The aim of this work is to propose a methodology for evaluating inhomogeneity due to the sedimenta-tion of fibres in High-Performnce Concrete (HPC) mixtures. HPC mixtures makes better mechanical-physical properties than ordinary concrete. To achieve higher strengths, the fine-grained matrix is rein-forced with the reinforcement – fibres. The type of used fibres and their homogenization in mixture has an influence on the final mechanical properties of HPC mixture. Four concrete mixtures with same com-ponent proportion was chosen for experiments. Water was the only one component, that was changing in mixture recipes. Steel fibres with a ratio of the diameter to length = 0.3/20 were used as reinforcement. The fibre volume in mixture was 1.5 %. The microscopy analysis was used for evaluation of the fibre dis-tribution in the test specimens. It was obtained, that the concentration of the fibres increases with dis-tance from the surface to the bottom of the HPC structure and this non-homogeneity increases with higher water dosage. The dependence of sedimentation of fibres on composition of HPC mixtures can be used for evaluation and optimization of final mechanical properties of the HPC structures.

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.

The aim of this article is to approach the measurement of forces and pressures of collaborative robots. In the article, research will be carried out on measuring the forces and pressures of a collaborative robot before putting it into real application. Force and pressure values will be measured using appropriate measuring devices. The measured results will be compared with the ISO/TS 15066:2016 technical specifi-cation and subsequently evaluated.

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 article deals with a possibilities of an enhancement of functional properties of highly stressed components by specific combination of surface technology. Two surface technologies such as plasma nitriding and laser shock peening were selected for the experiment. Those technologies were applied upon steel 42CrMo4 frequently utilized in manufacturing of strained components. Properties obtained by applied surface technologies were tested by following experimental methods. The chemical composition was verified by optical emission spectrometer Tasman Q4 Bruker. The surface morphology was inspected by scanning electron microscope TESCAN MIRA 4. The microstructure of heat treated as well as of nitrided specimens was observed by opto-digital microscope Olympus DSX500i. The microhardness profiles were measured by microhardness tester LM247 AT LECO. The friction coefficient was tested on tribometer Bruker UMT 3 TriboLab. For an assessment of the surface wear resistance the profilometer Talysurf CLI 1000 and Contour GT were utilized. The experimental results show that although the proposed surface technology combination manifests itself to be disadvantageous, both technology LSP, as well as plasma nitriding, applied separately, can lead to a significant wear reduction.

Aiming to study the influence of ultra-precision grinding parameters on the accuracy between the same clamping method and different workpiece sizes. This paper mainly analyzes the difference between the measurement precision of different parts by the same measurement method and the measurement precision of the same parts by different measurement methods. Therefore, the influence of grinding parameters on grinding precision is reflected. For the same part, it is concluded that the coaxiality error coincidence degree at end A and end B reaches 90.32% and 95.27%, respectively by using precision three-coordinate measuring instrument and Mahr roundness instrument. The coincidence degree of end A and end B verticality error reached 97.54% and 91.08%, respectively. For parts with different sizes, the Mahr roundness meter is used for measurement. The analysis shows that the coaxiality coincidence at end A and end B is the highest, reaching 98.36% and 92%, respectively. And from the analysis, the errors are mainly reflected in the factors such as jig and fixture and grinding process.

Thin sheets of aluminum alloys are widely used for the packaging of pharmaceutical and cosmetic products and in the food industry; however they present critical issues during the forming process. The blow forming process, which is widely used in the glass and plastics industries and for the hot forming of metal sheets, allows solving the problems related to the lubrication and the small tolerance ranges of the tools required by the well-known deep drawing process to form a thin sheet. In this work, the blow forming process is proposed for the first time to cold form thin metal sheets. Its advantage is connected with the use of equipment with a simple shape and, therefore, less expensive. Specifically, this work evaluates the time needed to form a simplified part; this is a critical aspect to apply this forming process to the food packaging industry. Moreover, this process represents the first step to developing a method-ology for evaluating the constitutive equation of thin sheets as an alternative to tensile test that has some critical issues connected with specimens’ manufacturing and test carrying out.

According to the application requirements of SOC in lithium batteries of Unmanned Aerial Vehicle (UAV), an Extended Kalman filter-Double Kalman filter (EKF-DKF) composite model was proposed to optimize the accuracy of the last 20% stage of State of Charge(SOC) estimation. Based on the equivalent model of second-order resistance-capacitance (RC) circuit improvement, the developed method optimized the identification accuracy of parameters, and set up a MATLAB simulation platform to jointly estimate SOC online with EKF and DKF. The data obtained in laboratory test environment were used for simulation.

The growing use of composite materials in various industries implies the necessity of conducting research on both their manufacture and subsequent machining. One of the main problems in composite machining is the selection of a suitable cutting tool. This study investigates the effect of the geometry and material of a milling cutter on the quality of a milled composite part. A carbon fiber-reinforced epoxy resin matrix composite was tested. Two cutting tools were used: an end mill with PCD inserts with a diameter of 12 mm and the number of teeth of 3 as well as a PCD-coated carbide end mill with a diameter of 12 mm and the number of teeth of 4. Variable technological parameters were used. The quality of the machined surfaces was assessed based on burr height and selected profile roughness parameters. Results showed that for the milling process conducted with the same technological parameters, the surface quality obtained with the 4-tooth PCD-coated carbide tool was higher than that obtained with the 3-tooth tool with PCD inserts.

In this paper, the adhesive behaviour of different polyurethane glues was studied and compared. The study was inspired by real conditions in the production of car windows, and it is divided into several parts, which deal with three types of polyurethane adhesives. The first type is a standard one-component polyurethane adhesive, which cures with air humidity. The second type is a one-component polyurethane adhesive with the addition of a curing accelerator. And the third type is a two-component polyurethane adhesive. Adhesive blocks of defined dimensions and plastic parts glued to the glass were used for this experiment to simulate a real product. The influence of temperature and humidity on the curing process was evaluated. The test included measuring the force required to tear the parts from the glass and assessing the type of failure. Based on the achieved results, the adhesives were evaluated regarding their applicability in the real automotive industry and the key properties necessary to maintain the safety and quality of the glued part were determined

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.

Joining technologies are very important aspects of production process in the automotive. Especially regarding the use of newly developed types of materials (e.g. ultra high-strength steels or aluminium alloys), in addition to welding technology, e.g. riveting or adhesive bonding technologies are used. Submitted article evaluates the effect of the riveting force on the final quality of riveted joint when joining aluminium alloy EN AW-6016 (thickness 2 mm). The actual evaluation of the riveted joint was carried out using a shear test, measuring the hardness HV01 and deformation analysis of specimen using non-contact optical scanning (ATOS III Triple Scan system).

Traditional assembly sequence solving methods often face problems such as combinatorial explosion and low efficiency in solving complex products with multiple parts. To improve the level of assembly sequence planning (ASP), an interference matrix is established to express the basic assembly information of a product. Taking the stability of the assembly sequence, the number of assembly direction changes, and the number of assembly tool changes as evaluation indicators, a fitness function is constructed. An improved particle swarm optimization (IPSO) approach for ASP is developed based on the peculiarities of the ASP issue. Redefining particle positions, velocities, and their update operations, and introducing mutation operators in genetic algorithm (GA) to improve the ability of PSO algorithms to jump out of local optima. Furthermore, the algorithm's convergence speed is enhanced by adjusting the value of the inertia weight. Finally, an example is provided to demonstrate the IPSO algorithm's usefulness and efficiency.

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.

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.

The paper presents the results of an experimental work on the assessment of microscopic morphology of the surfaces obtained as a result of cutting with a Water Jet (WJ) water abrasive beam. The examination of microscopic structures was carried out with the use of Nova NanoSem 450 scanning electron micro-scope. The subject of analysis were the interfacial structures of multilayer structures connected in a vul-canization process with the surface of thin-walled parts made of AW-5754 aluminum alloy. The results of the research were compiled as a function of the technological WJ cutting conditions, such as feedrate and abrasive material flow.

In recent years, 3D printed arm casts can replace traditional arm casts to treat bones fractures. 3D printed arm cast modelling often uses professional 3D scanning systems to capture 3D data of the arm. These systems are very expensive and may not be available in many hospitals. In order to over-come this disadvantage, inexpensive methods should be developed. This paper introduces a new data collection method based on smartphones. The photos of an arm were taken with a smartphone cam-era using some special techniques that could facilitate the process of image processing and 3D mod-elling in Agisoft Metashape and CATIA. To validate the proposed method, the photogrammetric model was compared with the scanned model (obtained by a low cost scanner) in GOM Inspect. Be-sides, a fit check of real 3D printed arm casts attached on the volunteer's forearm was also per-formed. The test results indicate that the photogrammetric model could be used as raw data for 3D arm modelling.

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.

Aiming at obtaining ultra-low kinematic stiffness and improving the isolation property of low frequency vibration, it is necessary to solve the coupling parameters and rated load of air negative pressure characteristics and rubber characteristics, in order to achieve an ideal elastic characteristic curve of air negative pressure spring. Firstly, the background and working principle of the negative pressure rubber isolation were introduced. In addition, the FEA model of isolator is built based on Mooney-Rivlin constitutive model of rubber. Furthermore, to testify the validity of the mathematical model, the static characteristic and simulation analysis of isolator are studied. The experimental data and characteristic curve of different negative pressure were obtained, the simulated results show a good agreement with those of corresponding experiments. Finally, they also illustrate the validity of the vibration isolation, which realizes better performance of low-frequency vibration isolation.

Additive manufacturing is a relatively new technology that has recently undergone noticeable develop-ment, which includes several types of technologies based on the gradual deposition of material in layers. The most widespread method is Fused Filament Fabrication, which belongs to an extrusion technique. The typical feature of extrusion methods is material deposition in the filaments form. Therefore, printer users cannot apply the same approach to products as with conventional technologies. The authors of the paper have been working with the mentioned technology for several years. The primary goal of the research is the investigation how printing parameters affect the mechanical properties of laminates reinforced with chopped carbon fibres. Based on experience and knowledge, the authors report in this article the most common challenges encountered in the preparation process of specimens for tensile testing. This knowledge can also help ordinary users of 3D printers, who also face these challenges without being aware of the impact of these pitfalls on mechanical properties.