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The aim of the article is to analyze the friction welding process of steel pistons, due to the small amount of scientific literature on this subject. First, it is necessary to present the design fea-tures of steel pistons and their advantages and disadvantages. Then analyze the types of friction weld-ing processes used in the production of pistons of internal combustion engines with the analysis of their differences. Present two basic methods of welding in the production of steel pistons, i.e. friction butt welding and low pressure friction welding. Finally, a proper analysis of the friction welding pro-cesses of steel pistons of internal combustion engines can be presented. At the end, the conclusions of the analysis are presented and proposals for improving the process are made.

Polyvinyl butyral is a material that is widely used in the manufacture of laminated glass sheets. Polyvinyl butyral film is widely used as an intermediate layer for laminated automotive or architectural glass. The intermediate layer primarily ensures the safety function of the laminated glass. Other advantages of laminated glass with a polyvinyl butyral interlayer include that it can be adapted to perform other functions, including acoustic functions, anti-reflection functions or functions enabling information to be projected on the glass with this interlayer. In this work, the influence of further processing of polyvinyl butyral film with non-uniform thickness is studied. Further processing may have a negative impact to the profile of PVB material.

The article presents results of the use ABC method applied to technological machines modernity level assessment in anti-corrosion protection of steel structures. Research findings enables identifying and analysis of the technological modernity level of machines used in the anti-corrosion protection process that is crucial for the final quality of the process and product manufactured in the steel construction production. The paper proves effectiveness of using ABC method of the machines modernity level as-sessment in the analysis and improvement of the steel construction corrosion ensuring process.

Stress corrosion cracking (SCC) is a common cause of structural failure. The simultaneous action of the corrosive environment and tensile stresses creates cracks that have an intercrystalline or transcrys-talline character. These are cracks with a fragile morphology of the fracture surface without signs of plastic deformation in their vicinity. SCC cracks occur in several alloys. This paper focuses on copper alloys in which this type of failure occurs frequently. Examples from practice show cases where the occurrence of SCC violation was related to the conditions of use of components and their production technologies. The paper does not aim to capture all the influences associated with the occurrence of SCC failure of copper alloy products.

Experimental studies of the wheel rim workpieces with additional technological corrugations have been carried out the results of which showed the ineffectiveness of this technique in profiling to increase thickness of the radial profile junctions of the semi-finished product. The comparison of profiling methods was carried out according to the Cochran's criterion and Student t-test. The additional experiments aimed at the determination of the flexural strain on differently shaped workpieces confirmed the impossibility of creation of the upthrust in the meridional direction during the deformation of the closed shells with straightening of the technological seats (corrugations). It is determined that the seats on the shell unbend in the tangential direction, the bending moments are damped nearthe site of the load application.

In this research work, a heuristic method based on biologically motivated Particle Swarm Optimization (PSO) has been proposed for edge detection using multiresolution decomposition, to enhance the quality of the images for predicting surface roughness parameter Ra from Ti-6Al-4V turned surface images. First level Dual Tree Complex Wavelet Transform (DTCWT) is used to decompose the turned images to generate new sub band images. The performance of DTCWT with PSO method is examined for turned surface images and compared with conventional edge detectors like Canny, and Sobel methods along with Discrete Wavelet Transform (DWT) with PSO and DTCWT without edge detection. The obtained results showed that, DTCWT with PSO based edge detection provides better looking edges and also best results are obtained in terms of Root Mean Square Error (RMSE) and Peak Signal to Noise Ratio (PSNR). Further, statistical features have been extracted from the images subjected to proposed edge detection method. The extracted statistical features along with machining parameters and tool flank wear have been given as inputs to radial basis function neural network (RBFNN) to predict Ra of the turned surface images.

Providing products with higher quality and lower prices is considered to be a competitive advantage for the industrial firms over competitors. This main challenge can be achieved by minimizing the overall production costs and operational time. Lean manufacturing provides many tools and techniques to iden-tify and eliminate wastes and to reduce costs in production systems. In this paper, single minute ex-change of die (SMED) technique is used as a lean manufacturing approach in a leading Palestinian aluminum profiles company. SMED was implemented through real experimental procedures applied to the extrusion line processes to investigate its effect on decreasing the setups time and improving the Overall Equipment Effectiveness (OEE) of the extrusion machine, in addition to introduce a guide for practitioners to improve the extrusion process dies exchange in similar industries. Overall, the successful implementation of SMED resulted in an increase of OEE by 3.26% as the consequence of the increase of machine availability by 4.86%.

There are a number of methods for measuring propeller pitch but it could be a problem for many fishing boat builders who lack of professional equipment. This paper presents a method of propeller pitch measuring based on photogrammetry and CAD (Computer Aided Design). This method con-sists of three stages. At first, a series of photos of the propeller were taken by a smart phone. After that, these 2D images were processed by a photogrammetry software to create the 3D virtual model of the propeller. Finally, in CAD environment, the pitch at different radii of each blade of the 3D vir-tual model were measured. To validate the proposed method, several propellers for fishing boats were measured and the measuring results were compared to those archived by using an EDM (Electrical Discharge Machining) machine and by a highly skilled man with simple tools. The measurement results show that the proposed method could be acceptable for measuring pitches of propellers of fishing boats.

Planning a process of production, among other machining processes, is an important stage in the production of products. The developed machining process should allow production of parts with the planned dimensional accuracy and specified surface roughness. With reference to the above, the scope of the carried out theoretical work included determining the dependences between parameters of the drilling process, tool wear, as well as the impact of these parameters on the hole quality. The main aim of experimental research was to analyse cutting tools wear in various phases of tool usage. The research consisted in observation of metallographic microsections to analyse changes occurring in the drill bit microstructure. Then the microhardness was measured and in the next step the micro-hardness of the tested drills was statistically compared. Based on the results obtained, the percentage of wear for drill bits depending on microhardness was estimated taking into account the earlier esti-mated Percentable Production Cycle (PPC). This allowed determining the degree of wear and tear of drills by comparing the microstructure and microhardness between them. The aspects of cutting tool management are also discussed.

The present contribution examines the structures of and corrosion processes in copper-basalt composite laser claddings on a steel substrate. The cladding material was a laboratory mixture of the following components: Oerlikon METCO 55 (Cu > 99.9 %) + basalt dust. In this investigation, metallographic structures of copper-basalt composite laser claddings were studied using optical and scanning electron microscopy. The adhesion of the claddings to the substrate was testing using the non-standardized Mercedes test. A potentiodynamic corrosion test in artificial mine water was performed on a specimen of the composite laser cladding. The test results were compared against those for a reference high-purity copper standard and AISI 304 steel. The findings were interpreted in terms of the potential of using copper-basalt composite laser claddings as corrosion protection coatings on steel components in nuclear power generation.

The aim of this paper is an analysis of the dependability of critical components of the John Deer 7530 tractor. For this analysis data was used from a database which contains maintenance data of 166 trac-tors during approx 9 years. The first part of this article is devoted to the selection of critical compo-nents based on number of failures of individual machine parts for a given period and their sales pric-es. The next part of article presents data for calculation dependability indicators which contains oper-ating times to failure and operating times without failure. Due to the large size of the data files of the individual components, the data are only given for one machine component. Furthermore, the meth-od of calculation of dependability indicators is described by parametric statistical methods according to ČSN EN 61649:2009 and mean time to operating failure. The results of the analysis are summa-rized in tables and graphs. The method in this article can be used to optimise the maintenance pro-gram.

In the present study, local defects in deep groove ball bearings are studied as forward and inverse problems. To this end, the separation-integration method is applied for modeling the forward problem. It is assumed that the inner race of the rolling element is multi-DOF, while the outer race is deformable along the radial direction. Then the problem is modeled with concepts of the finite element method. The contact force for the rolling elements is described by the nonlinear Hertz contact deformation. Various surface defects originating from local deformations are introduced into the developed model. Since the outer ring can be coupled with the FE model of the housing, the developed bearing model is capable of considering the transmission path of the bearing housing. Then model parameters are modified to reach better performance in predicting local defects. Through translating the inverse problem into the comparison of the geometric distance, measured indicators are used in the defect detection process and the relative location and size of defects are predicted. Finally, the defect range is established to evaluate the fault severity. Obtained results demonstrate that the proposed method is effective and accurate in the studied cases.

The paper deals the production of porous aluminum materials that are characterized by lower density and mechanical properties. Samples of porous aluminium materials were produced on the basis of the developed methodology that applied sodium chloride particles of different sizes (average size 4, 6 and 9 mm). The AlSi12 foundry alloy was preffered for the production of the aluminium porous material. As part of the experiments, samples of porous aluminium material in the shape of a truncated cone were made. The cavity of the foundry mould was in the shape of a truncated cone with diameters: D = 0.047 m, d = 0.040 m and height v = 0.040 m. The material properties were determined on the produced samples. Their weight, volume and their density, relative density were calculated. Based on empirical relations, their value of Young's modulus of elasticity and value of thermal conductivity were determined. The compressive strength of selected samples was monitored as well. The value of Young's modulus of elasticity was determined from the measured stress-strain course. Furthemore, the porosity of the produced samples was evaluated on a scanning microscope.

Optimization is the process of finding the best possible solutions of a problem. It has been widely used in various areas especially in engineering problems. One of the common issues that is faced by some of manufacturers is finding drilling sequences of multiple holes. By drilling multiple holes with the least total path length, the manufacturer can save a lot of time and it can increase the productivity of the company. Thus, this study focuses on drilling path of multiple holes problem which has been solved by other researchers. This study uses the Bees Algorithm to find the best sequence of drilling holes (mini-mum total path length) and the results found are compared with the result of other algorithms. In addi-tion to results comparison with other algorithms, the results obtained are verified with simulation results using MasterCAM software. The results comparison shows that the Bees Algorithm achieved compara-ble performance compared to other algorithms.

Technological progress in the 21st century has catalysed the industrial revolution (Industry 4.0) following the development of multiple new industrial automation technologies in the manufacturing sector. Regardless, past research indicated the unsuccessful attempts in adopting Industry 4.0 technologies among manufacturing organisations. Undoubtedly, the operationalisation of Industry 4.0 in manufacturing proved challenging as organisations were required to evaluate various aspects for effective implementation. Thus, a sound understanding of constructs concerning employees’ acceptance and readiness levels towards novel automation technologies was required. Hence, this study aims to explore, develop, and validate the suggested conceptual framework by integrating the Technology Acceptance Model (TAM) and Technology Readiness Index (TRI) with Exploratory Factor Analysis (EFA). The EFA process was the first crucial step in ensuring the internal consistency and stability of the instrument across the sampling population. Consequently, the research outcome potentially enabled the manufacturing sector to identify and comprehend the key determinants in designing industrial automation technologies. This study also contributed to knowledge on technology acceptance by synthesizing TAM 3 and TRI 2.0 theories, thus constructing a new TAM in manufacturing.

This work deals with the construction of a steel hangar with a sheet metal shell for storage sports flying equip-ment (SPE) or general aviation aircraft. The design of the building was made to ensure an individual approach to each aircraft. The construction was designed with price and safety in mind. An available option is an electronic security system connected to the central security desk via the Internet, mobile phone or other data transmission.

The aim of the article was to check the internal defects in the butt welded joints by non-destructive TOFD (Time of Flight Diffraction) technique. Subsequently, the macrostructure from the defect indication site was evaluated and assigned to the TOFD ultrasound indication. Basic knowledge of ultrasonic TOFD testing are described in the theoretical part of a submitted paper. Ultrasound technique TOFD is non-destructive method that can detect internal defects inside test material without damaging it. It is a reliable method for detecting mainly flat internal defects such as incomplete root penetration, lack of fusion, etc. Ultrasonic test procedures and test results obtained in non-destructive testing of butt weld are shown in experimental part. Evaluation of the ultrasonic TOFD testing results, its advantages and disadvantages are described at the end of this article.

Nowadays, foundries do not sufficiently utilizes computer support during the creation of technical documentation. Instead of computer documentation, foundries are using classical method for designing technological documentation and the computer aid is only discrete. For the area of foudry technology, it is inappropriate to use conventional CAPP systems which use group technology because they work with a simple representative selection from the database according to the characteristics. The submitted article shows a solution for systems interconnection and the possibilities of using the simultaneous engineering for aircraft industry. A new system was designed serving as the creation tools for technological documentation, whose role is to effectively benefit from group technology with use of latest software capabilities.

Prototype production is a key element in the process of developing a new product. The prototype is important both for the initial materialization of ideas and intentions for product design, as well as for subsequent assessment of the technological design of this design. 3D printing technology is also used today as a suitable technology for prototype production, especially for the possibility of relatively rapid adaptation to complex shape geometries, the ability to produce what would be difficult or impossible to produce with conventional technologies, and last but not least, the increasing availability of 3D printing equipment.This paper demonstrates the principle of production of auxiliary gauges, for checking the dimensions of a prototype product with complex shape, 3D printing and its further possible use in the conditions of an engineering company. The conclusions of the paper should show the possibility and suitability of integration of modern and classical production technologies in the conditions of piece or custom production.

This paper proposes a control strategy for single-phase off-grid inverter, which integrates the three closed-loop control with the iterative-based RMS algorithm. The inverter circuit is modeled, and simulation experiment and prototype verification are performed on Matlab. The results show that the voltage drop problem caused by an abrupt variation of inverter load is improved greatly owing to the addition of voltage RMS loop. Meanwhile, the application of iterative method enhances the dynamic response performance of the system substantially; and improves the real-timeliness of three closed-loop control. The two complement each other to provide a highly effective, reliable control solution for the single-phase off-grid inverter.

Very dynamic development in the field of computerization and industry robotization, as well as an im-plementation of the Industry 4.0 assumptions are the main reason for the increased demand for magnetic materials. The limited rare earths availability and the sustainable development in the field of material engineering indicate that the methods of recycling magnetic materials from Waste of Electrical and Electronic Equipment are necessary. This paper presents the impovement stages of magnets recovery process - extrusion process of magnetic scraps/particles with polymer (magnetic scraps and particles obtained from WEEE). The process is developed based on the Process Failure Mode and Effects Analy-sis. The reserch pointed the irregularities, that pose the greatest risk of failure in the process. The paper presents changes in the process based on the values of the indicators: severity (S), probability of occur-rence (O), probability of detection (D) and the Risk Performance Number (RPN). Based on the PFMEA, 5 operations were added to the process. Due to changes in the process course, it is possible to minimize the effects of the irregularities occurrence.

This research focusing on influencing the surface structure and its geometric deviations from the CAD model after various tumbling of bodies at constant parameters of the tumbling machine. The purpose of determining the actual effect on the resulting surface before and after the tumbling pro-cess, which tumbling body causes the selection of a larger grain or compaction of the surface layer. The research outputs are thermographic maps and geometric deviations measured using CAD mod-els. The experimental line was at VŠB - TU Ostrava, with the help of the PROTOLAB 3D printing center, there was an experimental sample in your game. Measurement of access in the metrology laboratory on CMM Wenzel LH 65 X3Premium and optical heads Shapetracer II.

Lower bracket is an important component in hydro generator. Taking lower bracket as the research object, the strength, the stiffness and the dynamic characteristics of lower bracket have been simulated and analyzed by means of establishing a finite element model. With the two design indexes of maximum normal stress and stiffness as the constraint conditions, aiming at an optimized design with the minimum mass and proposed a lightweight optimization method. The design parameters of the optimized model of hydro generator lower bracket are determined by using the compound form method with optimization iteration. Through lightweight optimization design, the maximum normal stress and maximum displacement of lower bracket are within the allowable value range, modal analysis shows that the dynamic characteristics of the optimized structure also meet the requirements, with the potential of material further utilized. The lightweight optimization design reduced the weight of lower bracket in hydro generator by 790kg and the weight-loss ratio reaches 44.38%, thus achieving the purpose of lightweight. The optimization results are applied in the improvement design of lower bracket and the method is practical and suitable for engineering applications.

Projection welding belongs to the group of resistance welding technologies. The basic process parameters are the welding current and the current flow time. Although the resistance projection welding of nuts on galvanized steel sheets is widely used in industry, only a few research articles have been published. The resistance projection weld-ability of the fasteners on metal sheets is not as well understood as the resistance spot weldability of the sheets, so complex studies for the wider application of resistance welding of nuts in the automotive industry are still needed. This research is aimed at valuation the effect of resistance projection welding parameters (steel nuts on galvanized steel sheet DP 600) on joint properties. The hard welding mode (high welding current, clamping force and short welding time) provided 2 times higher strength of the weld joints as the soft welding mode. When using the soft welding mode, an increased Zn concentration from the sheet metal coating was measured in the transition area between the welded materials at the folding locations. When applying the hard welding mode, only a slight in-crease in the Zn concentration was observed at the inner boundary of the weld joint.

The given paper deals with the wear of the tensioner which is produced from aluminium alloy and used of the motorcycle timing chain. This component was made due to the unavailability on the spare parts market. The AlMgSi1 alloy was chosen for this purpose, taking into account the requirements for producing of the tensioner. After production, the tensioner was put into operation where its functionality was regularly controlled. The suitability of the selected material was checked after the tensioner was removed. Possible damages and structural changes in the material were assessed using a scanning thermoemission electron microscope. Detection of the chemical composition of foreign particles trapped on the surface of the tensioner from engine oil during the operation was performed by EDS analysis.

The objective of this paper was to investigate and respond to the quality and strength of CMT welds that were sub-jected to degradation effects and subsequently to tensile testing. The tensile test was recorded using AE acoustic emission. The experiment focused on the quality of CMT welds (Cold Metal Transfer) and the resistance of these welds to corrosion degradation. Welds are generally exposed to environmental influences such as high stress, stress and degradation effects. The combined effect of these factors may in some cases result in the destruction of weld joints. For this reason, emphasis is placed on the quality of welds and their resistance to environmental influ-ences. For this measurement there were ten samples prepared, divided into two groups, each having five samples. One group was subjected to corrosion degradation, while the other one was at the same time subjected only to envi-ronmental influences. Subsequently, all samples were subjected to tensile testing. The course of this test was rec-orded using the AE acoustic emission, where the AE sensor was attached to each weldment to record dislocations during the tensile test. Named values were evaluated in the Dakel–Daeshow program.

The aim of the paper is to introduce the digital twin concept as part of the Industry 4.0 strategy. In the form of a case study, the procedure and outputs of the simulation of a specific production plant to-gether with its intermediate storage and output for the next plant are presented. In the research part is presented a simulation model of production lines and intermediate stock with material flow represen-tation. At the beginning of the research the analysis of production and logistics processes was carried out. The next part describes the programming methods used to record and redirect material flows between individual lines and stock. The simulation method using simulated production line models enables the digitization of dynamic production processes in enterprises. We expect that in the coming years there will be an increase in demand for the creation of simulation models of production systems in modern manufacturing companies that will try to implement the Industry 4.0 strategy and thus in-crease their competitiveness.

This paper deals with basic methodology of surface evaluation of functional surfaces, which were prepared by various machining methods (turning, milling and grinding). Here are the basic 2D (profile) parameters and 3D (spatial) parameters and their properties in relation to the machined surface. Parameters of machined surfaces were obtained by CCI Lite Coherence Correlation Interferometer from Taylor Hobson and evaluated using the TalyMap Platinum software. The article further demonstrates the inappropriateness of the surface structure assessment with only the parameter Ra (mean arithmetic deviation of the profile), which is the most common method in technical practice. This methodology extends the possibilities of a comprehensive assessment of exposed surfaces of machine parts.

This paper deals with different ways of injection molding. A plastic part can be generally filled many ways. Use of more than one gate is common in a plastic industry. Cascade molding can affect the final properties of the product, especially by the number of gates, timing of closing - opening and by the order of individual gates. A simple plastic box is used as a reference part in this paper. It is a longitudinal part with one side longer than the others. There are ribs on the bottom side of the box. The injection system is located on the bottom side of the box. The filling process is considering five individual gates. All possible filling variants are compared with respect to temperature, pressure and number of weld lines. Sequential filling from the central point of the box is the most suitable option.

The heat treatment of the heat-treatable aluminium alloy forgings includes cooling from the solutionising temperature. After heat treatment, residual stresses remain in the forging, which are due to temperature gradients during cooling. The effect of these residual stresses on the forging properties can be significantly influenced by other technological operations, including artificial aging, machining, and surface treatments. The influence of the surrounding environment can also play an important role. Because in connection with the residual stresses after heat treatment we often encounter cracks in forgings, this paper is devoted to an overview of factors that influence cracks. The typical examples of damaged forgings are discussed and explained the circumstances that caused cracks under the influence of residual stresses.