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The article presents the results of the use Six Sigma DMAIC cycle to improve workplace safety and decrease the cost associated with work accidents in the company from the automotive branch. Selected tools of the DMAIC cycle were used at each stage: the project card and the Pareto-Lorenz diagram at the define (D) stage, the matrix diagram at the measure (M) stage, the Ishikawa diagram with the verification of causes at the analysis (A) stage, the 5WHY method at the improve (I) stage and the c control chart at the control (C) stage. Each of the successive stages was based on the results of the previous one in order to achieve a lasting solution for the analysed problem by the implementation of remedial measures. Because of the implementation of remedial measures, the level of work safety in the examined company was improved. The DMAIC analysis made it possible to identify the main causes (Xn) of accidents at work and to objectively evaluate them in order to discover the root cause (Xn!) of the problem. The root cause turned out to be inadequate protection of the lathe due to the protective cover installed too far away from the lathe chuck, which resulted in the catching of protective sleeves or gloves of the lathe operators and accident events in the form of upper limb damage. The solution to this problem was to reduce the gap between the guard and the lathe chuck by adjusting the guard so that no more items of workers' clothing were caught while the machine was running. The article proves the effectiveness of using the Six Sigma DMAIC cycle in analyzing and improving the state of occupational safety and is an incentive to use this cycle and a specific set of tools to analyze similar problems.

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.

Over the next few years, LEDs are likely to be responsible for all of the vehicle's exterior lighting func-tions. Everything is focused on maximum security. For this reason, there are more and more automatic color detection systems in the car. Proper color separation is the key to optimal operation and proper evaluation of these automatic systems. An example is the correct detection of traffic light colors. The automotive industry is dependent on consistency and predictability. Classification is an important func-tion for automated control and requires the correct color resolution of the signals captured by the camer-as. We propose to use glass containing various colored active substances such as Eu2O3, Tb2O3 and Sm2O3 as color filters for LED diodes. LED source from one visible light area to another visible light area. This study is devoted to the production of photoactive glass. Subsequently, the photosensitivity of molten photoactive glasses is tested. Both the absorption and excitation spectra of selected photosensi-tive glasses are measured.

After the Fukushima accident in 2011 year, ATF nuclear fuel cladding concept was accelerated to achieve the reactor operation with the new accident tolerant structural materials. However, several designed solutions do not fulfil the accident tolerant concept but particularly increase the corrosion resistance of Zr-cladding tubes at normal operating conditions, so-called “Advaced Technology Fuel, EATF”. Cr-coated zirconium claddings following the first concept, have been the widely tested and the first full Cr-coated fuel rods have been planned to operate in LWR reactor conditions around the 2022 year. Our contribution describes the Cr-coated Zr-%1Nb cladding tube microstructure after high-temperature steam oxidation at 1200°C by means of Scanning Electron Microscopy and nanoindenta-tion methods. The article is focused on WDS line-profile studies of oxygen and chromium diffusion into the Zr-matrix. The increased Cr-diffusion with oxygen is evident causing a change in local me-chanical properties which is well-described by measurements of nanohardness and Young's modulus. In addition, the developed methodology of the WDS & nanoindentation line-analyses was also opti-mized to apply in hot-cell conditions to measure the effect of neutron-irradiation on the different coat-ings and coating/matrix interface.

Deep-sea nodules are ores formed on the sea floor at depths of 3000 to 6000 m as a result of sedimen-tation. They range in size from 1 cm to 15 cm and contain mainly manganese and iron and other ele-ments that are collected from the nodules by complex pyrometallurgical and hydrometallurgical pro-cesses. These other elements of interest are bound in the nodules mainly in the form of manganese and iron oxides. In order to achieve a high yield of metals bound in nodules in the form of oxides, it is necessary to disintegrate this arrangement in the lattice. This can be achieved by exposing the deep-sea nodules to a reducing condition. This paper deals with the one-step recovery of metals of interest from nodules using silicothermic reduction with 10% excess silicon over stoichiometry. The phase composition, microstructure and mechanical properties of the obtained reduced material were determined.

The given paper deals with the issue of materials used in the treatment of heart attacks. In more de-tail it focuses on individual types of stents and their specific properties. The article describes selected groups of biocompatible metal-based materials. Our attention is mainly paid to magnesium alloys. The introduction explains the concept of biocompa-tibility and the distribution of materials accord-ing to their biological tolerance. In the experiment, we performed an ana-lysis of the chemical com-position of individual metal stents and focused on examining their wear resistance. Since it is too difficult to imitate human body environment, we opted for corrosion test for the experiment. Stents were exposed to the given concentration of the solution and temperature. The time period during which the stents were in solution was also important. In the final part, we focused on the microscopic evaluation of the surface.

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.

When measuring roundness, accurately adjusting the measured part is very important. The axis of the measured part must be perpendicular to the section where the roundness is measured. If this fails, a systematic error will occur. It depends on the size of the inclination of the surface during the meas-urement. The paper presents mathematical relations to calculate the error when measuring roundness on a cylindrical and conical surface. It analyses the influence of the inclination and the parameters of the measured area on this error. The theoretically determined values are compared with the practical-ly measured roundness values. The error harms the accuracy of the roundness measurement. It af-fects the value of roundness, but also the roundness profile itself. It is explained that the mistake can not only increase but also decrease the measured value of roundness, in conclusion.

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.

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.

Precipitation hardening is one of the most frequently used methods of the post-processing heat treatments of 3D printed tool steel 1.2709, as it increases the yield and ultimate tensile strengths of the steel. Within this work, the broad temperature range of 250°C – 550°C was tested with five differ-ent holds at each temperature to study the effect of processing parameters on the microstructure and mechanical properties. Maraging tool steel 1.2709 was produced by selective laser melting (SLM) technology and obtained results were compared with conventionally produced steel of the same chemical composition. Mechanical properties were established by hardness measurement and tensile test and the microstructure was characterised mainly by light and scanning electron microscopy. The peak hardening was for both steels reached after 6 hours of precipitation at 500 °C, however, apparent hardening effects of heat treatment were observed already after low-temperature heat treatments.

Mechanical alloying and subsequent compaction with spark plasma sintering was chosen for the fabrication of investigated CoCrFeNiTi alloy method. The alloy was characterized in terms of chemical and phase composition with X-ray fluorescence spectroscopy and X-ray diffraction spectrometry, respectively. The microstructure was examined using light microscopy and scanning electron microscopy equipped with an energy dispersion spectrometer. The alloy showed an ultra-fine grained uniform microstructure composed mainly of an FCC solid solution with a volume fraction of HCP Laves phases. Regarding mechanical properties, the prepared specimen reached an ultimate compressive strength of 1340 MPa with the hardness of 757 HV 30. The wear rate of the sample reached 1.19 · 10-4 mm3·N-1·m-1 showing traces of adhesive-abrasion wear mechanism.

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.

The quenching and partitioning (Q&P) process is an advanced method of heat treatment of high-strength steels. The resulting properties of Q&P-processed steels are dictated by their microstructure which consists of tempered martensite, fresh martensite and retained austenite (RA). These phases arise from individual steps of the Q&P-process. An important step is stabilization of retained austen-ite because RA raises ductility to above the levels found in conventional steels upon quenching and tempering. If the desired stability of RA is to be achieved, Q&P processing must not initiate compet-ing processes associated with carbide precipitation or austenite decomposition into bainite-like mi-crostructure. Yet, it appears that the very decomposition of austenite into bainite is an accompanying process that takes place at the partitioning stage, the stage which plays an important role in terms of mechanical properties of Q&P-processed steels.

Today, the emphasis is on the production of materials that are degradable in nature and on produc-tion with modern technologies. In order for these materials to find a suitable use, they need to be exposed to the conditions that may arise in the application. The effect of degradation was assessed for composite materials with a PLA matrix and a natural-based filler, which were processed by 3D printing technology. The progress of degradation in the climate chamber was monitored over a peri-od of 6 weeks. The results are determined by static tensile test and hardness test and the difference in weights of the test bodies. The test results confirmed. During the degradation process, the test spec-imens with natural fillers deformed less than the specimens made of pure PLA. The maximum ten-sile strength values for the material with natural fillers were approximately two thirds lower than for pure PLA. The maximum tensile strength during degradation showed an increasing or stagnant ten-dency. the maximum elongation decreased during degradation for the material with fillers showed a logarithmic behavior compared to pure PLA with a linear tendency.

This article deals with the influence of the mold material on the segregation process in selected Al-Si alloys. Three types of Al-Si alloys were chosen in order to compare the segregation process while congealing. AlSi7Mg0.3, AlSi7Cu4 and AlSi10.5Cu1.2Mn0.8Ni1.2Pb0.5 alloys were cast by gravity casting in a metal and sand molds. Macroscopic and microscopic analysis of the internal structure of each of the alloys was also studied. The chemical composition within the lower, middle and upper parts of the casts were observe by using scanning electron microscope. All samples were subjected to the Vickers microhardness measurement of a solid solution of α(Al). The distance between the secondary axes of the dendrites DAS (Dendrite Arm Spacing) was used to evaluate the level of segregation.

The proper design of the gating system including the tempering and venting of the mold significantly influences the final quality of the casting and economize the costs of the foundries. The initial numerical design of the gating system is often sufficient for creating of the documentation for the mold design, but without the practical experience of the designer, it does not reveal the hidden problem emerging from the melt flow through the gating system as well as the temperature and gas mode of the mold.The contribution is dedicated to the optimization of the runner dimensions determined by the numerical calculation. The theoretical part presents the methodology, based on which the gating system was designed for a particular type of the pressure casting. The experimental part is dedicated to the influence of the cross sectional area of the runner on the change of the melt temperature before entering the ingate. It was assumed that the larger runner cross section gives the melt greater volume and heat capacity and thus the melt enters the ingate with the higher temperature. The obtained temperature results are then compared witht he melt flow rate values, based on which an optimal sulotion for the runner design dimensions is determined.

The fundamental goals of face milling such as high surface quality, dimensional accuracy and productivity can be attained by proper regulation of process parameters, mainly feed rate, depth of cut and cutting speed, but also by taking into consideration the particularities of workpiece material and by selecting the cutting insert with the appropriate geometrical characteristics such as angle κr, rake angle and nose radius. In the present study, the focus is set on the comparison of three different commonly used milling insert types, namely rectangular, round and square regarding cutting forces under various process conditions, with a view to quantitatively evaluate their performance regarding cutting forces and specific cutting forces during face milling of steel workpieces and eventually determine which insert type leads to lower power demand for the same material removed volume. The findings of the present study indicate that the most favorable insert type is the rectangular one, followed by the square and the round one.

The traditional Mixed-model Assembly Lines (MMALS) balancing and sequencing serial design methods are difficult to adapt to rapidly changing requirements. From the perspective of the parallel design of balancing and sequencing, a mixed integer linear programming model for MMALS balancing and sequencing is proposed. An improved particle swarm optimization (PSO) algo-rithm was proposed, in the process of updating the optimal solution, the simulated annealing (SA) algorithm is added to make it possible to jump out of the local optimum with a certain probability and expand the solution selection to the entire population. Based on the algorithm, random coding and ascending decoding methods are proposed, the number of products and the number of tasks are coded and decoded at the same time. Verify the effectiveness of the algorithm by an example.

Corrosive damages can lead to accidents on pipelines in various industries. Therefore, the main objective of the work is to study the peculiarities of the development of internal corrosion at the corners of turns in steel pipes. The paper discusses the development of corrosion. It substantiates the primary importance of the development of corrosion on curved sections of steel pipes. It has been established that, in curvilinear areas, the rate of corrosion development depends on the rate of fluid flow, on the number of ions, and also on the effect of centrifugal force. The authors studied the average rate of corrosion development at the turns of hydraulic structures. Thus, the results obtained showed that the location of steel pipes of hydraulic structures affect the rate of corrosion development from inside the pipes.

Dynamic load of the improved hatch cover construction for universal open-box type wagon is researched, taking in to account the worse loading scheme - impact of 150 kg cargo from height of 3000 mm. In the case of improved hatch cover construction, dynamic load character reduction up to 50% can be reached, compare to conventional one. Hatch cover model of proposed construction for strength calculation was created. Strength calculation is done by finite-elements method in Cosmos Works software. Calculation of hatch cower durability, considering symmetrical and asymmetrical load cycle are carried out. In the proposed construction, areas with maximum equivalent stresses caused by usual operational load are defined. Results of conducted research can be useful for projection of new wagon generation with improved technical, economical and operational parameters.

The design of the gating system and the adjustment of the technological parameters of high pressure die casting are closely correlated. Correct connection of the gating system structure and technological parameters will be reflected in the final casting quality. Significant influence on the filling progress of a mold cavity has a gate and its geometry. Within the gate, the final increasing of melt flow velocity arises and determines the filling mode. The contribution is devoted to the influence of the gate height on selected technological parameters. The obtained data are being evaluated and on the basis of the experimental results assessment, the recommendations applicable in the foundry industry are being deduced.

The work presents the computer simulation results describing the motion of the interacting particles in a vortex fluidized bed (the constrained motion). The data obtained reveal the peculiar features of the polydisperse system motion in the apparatuses with the variable cross-section of the workspace. The empirical coefficient determining the residence time of a particle in the vortex fluidized bed was calculated. An algorithm of the residence time cal-culations for a particle in the vortex fluidized bed under the constrained motion is developed. The results of com-puter simulation were a part of engineering (technological and constructive) algorithm of calculation for the fu-ture manufacturing of granulator?s industrial sample.

The experiments aimed to verify the use of a focused ion beam (FIB) to create structures analogous to the natural surface and then use the two-step imprinting method to prepare replicas of the surface creat-ed by FIB. The surface of the petal leaves of pansy (Viola x wittrockiana) was selected as a natural sur-face pattern. The TESCAN AMBER FIB-SEM microscope was used for the preparation of an analo-gous surface. The molds for the replication process were made of President Light Body elastomer. PVB, PVA, CMC, PCL, EP were used for the preparation of polymer replicas. Scanning electron micro-scope was used to evaluate the quality of the prepared polymer replicas. The dimensions of the replicat-ed convex and concave structures were 25 x 20 µm. The polymers showed a different ability to copy the structure in detail. For PVA, CMC, and PCL, surface structuring at the nanometer level was described in this study. Due to the dimensions of the cones of convex and concave structures, the color was ob-served on all samples.

The AGVs or mobile robots are well used in today’s manufacturing supply technologies and also can be used in engineering’s education. The motion controlling and simulation of such vehicles are a cru-cial question. This paper introduces the steps of motion planning for a driverless carrier vehicle from the positions initially available to the speed of the wheels. The vehicle is located in the High-Tech Logistics Systems Laboratory of the Logistics Institute of the University of Miskolc. For motion con-trolling and simulation between two points the further modules are necessary: 1. path planner, 2. tra-jectory planner, 3. velocity-voltage converter using velocities gained from trajectory planner, 4. mo-tion controlling and simulation of a motor dynamical model using voltages from the converter, 5. simulation of the path and 6. data processing. In this paper the first two modules are detailed, i.e. the path planning and then the trajectory planning. Path planning is based on a new approach, using Bezier-curves and Hermite curves. The trajectory planning tends to the mininum energy, which can be carried out by the examining the current consumption created in the other modules. The smaller consumption originated from the two curves determines the final path and trajectory.

The article compared the strength results of single-lap adhesive joints made of galvanized steel sheet. The strength of adhesive joints was determined for two methods of surface treatment - using a degreaser (method B) and with-out a degreaser (method A). The samples were joined using a two-component epoxy adhesive based on Bisphenol A. The strength tests were carried out on a Zwick/Roell Z150 testing machine. The analysis of the surface roughness parameters of the samples for the method A was performed. The highest shear strength value (8.82 MPa) was ob-tained by method B and using P120 abrasive paper. The lowest shear strength value (4.08 MPa) was received using method A and P600 abrasive paper. The maximum values of measured surface roughness parameters were rec-orded for samples prepared with abrasive papers with granulations, respectively: P120, P220 and P180. The low-est values of Ra, Rz and Rt parameters gained using P600 abrasive paper.

This paper describes series of studies concerned with welding of Sc-modified AA2519 at the Military University of Technology. The modification of AA2519 alloy contains a higher concentration of scandium and zirconium and it has been developed in The Institute of Non Ferrous Metals, Light Metals Division in Skawina. The examination involves friction stir welding (FSW) and laser beam welding (LBW) of 5 mm thick AA2519-T62 extrusion. FSW process parameters were: 600 rpm tool rotation speed, 100 mm/min welding velocity, 4.8 mm depth plunge, and MX Triflute tool type. The used LBW parameters were as follows: 3.2 kW laser power, 1.1 m/min welding velocity, 0.2 mm laser beam width, 10° laser beam inclination angle, 10 L/min shielding gas (argon) flow with the laser beam focused on the workpiece surface (f=0). In this work selected results have been presented containing some problems and features typical for investigated joints. Butt joints produced by FSW and LBW have been compared in terms of microstructure (grains), microhardness distribution, joint efficiency, localization of failure, etc. The basic features of weld zones have been discussed together with the distributions of microhardness on the joint’s cross-sections. Both welding techniques cause a reduction of microhardness in the weld zone, but the drop from the base material’s value (135-140 HV0.1) is far higher in the case of LBW (85-90 HV0.1) than FSW (120 HV0.1). The established values of joint efficiency were 80% (376 MPa) and 66% (314 MPa) for FSW and LBW, respectively. The FSW joints tend to fail in the thermo-mechanically affected zone and LBW in the fusion zone.

In the performed experiment, changes in the microstructure of steels S265 and X6CrNiTi18-10 due to their chemical-thermal treatment by boriding were studied. The boriding process was performed in a Durborid boriding powder at 900 0C. During this process, surface layers of Fe-B borides were formed in both analyzed sorts of steels. The layers differed in their morphology and composition due to the different degree of alloying of the matrix of analyzed steels by additive elements. The formed Fe-B layers showed high adhesive and cohesive resistance in both materials. Due to changes in the micro-structure of S265 steel, especially due to significant coarsening of the original grain of its matrix, its resistance to tribological abrasion after the boriding process decreased. The opposite effect was ob-served for X6CrNiTi18-10 steels. As a result of boriding, both analyzed materials changed their corro-sion resistance.

This paper deals with a synthesis of a new ionising radiation attenuation composite material from Lu2O3 - Bi2O3 nanoparticles structure, that has never been described yet. The paper describes the preparation of Lu2O3 - Bi2O3 nano- and microparticles by three methods: a self-combustion synthesis, a solid-state method and a coprecipitation method. Polymer solution was prepared from Lu2O3 - Bi2O3 nanoparticles and Polyvinyl Butyral. Afterwards, nanofibers were processed by an electrospinning method from PVB - Lu2O3 - Bi2O3 polymer solution. PVB - Lu2O3 - Bi2O3 nanofibers were characterised and their X-Ray attenuation effect was tested. This paper proceeds from one of the author’s bachelor thesis.

The article deals with the design of a robotic workplace for laser engraving. The first part of the article describes the importance of introducing robotics to industry 4.0. Custom solutions work is devoted to the implementation of the six-axis robotic arm UR10. This six-axis robotic arm inserts the designed jig with the semi-finished product into the engraving machine. In the engraving machine, the semi-finished product is engraved on the final product. This saves the operator time to pinpoint the position of the semi-finished product inside the engraving machine. The proposed jig is designed to be universal so that the position in the x-axis and in the y-axis can be precisely defined. At the end of the jig there is a bed for placing the semi-finished product, which can be replaced by another in the case of other dimen-sions of the semi-finished product. The conclusion is a comparison of time savings in individual steps and overall engraving time savings for one engraved part.