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Ti-Al-Si alloys are among the most promising intermetallics, which show a combination of low density and good oxidation resistance. These positives predetermine Ti-Al-Si alloys for applications in the au-tomotive and aerospace industries. In the future, they could substitute existing materials for high-temperature applications (stainless steels, and especially nickel alloys), that high density significantly limits their application. The use of intermetallic compounds based on Ti-Al-Si would therefore lead in particular to a reduction of the weight of the structures, which is highly desirable in the aerospace indus-try. Due to the lightweight construction, fuel consumption and transport costs in general would also be reduced. The disadvantage of Ti-Al-Si alloys is their brittleness at room temperature. Decrease of brit-tleness can be achieved by suitable chemical composition and also by choosing the suitable preparation. Therefore, powder metallurgy processes appear to be the right way to prepare these intermetallics. This work deals with the preparation of intermetallic alloys based on Ti-Al-Si system with the low content of silicon by powder metallurgy using mechanical alloying and followed compaction by Spark Plasma Sin-tering.

Nowadays, to reduce vibrations of machines, damping devices utilize the eddy current damping ef-fect being increasingly investigated for its advantages of no mechanical contact, no viscous liquid required, high reliability, and good damping capacity. This article studied the main principle of the eddy current damping effect for a moving permanent magnet in a stationary and electrically conduc-tive nonmagnetic cylindrical tube. The magnetic damping coefficient is investigated experimentally, analytically, and by numerical simulations in a steady-state. The numerical simulation is performed in the ANSYS Maxwell programme. The obtained results indicate that the damping force affecting the moving magnet has a viscous form. The experimentally measured and computed results are in good agreement. The effect of varying tube diameter and the tube wall thickness on the magnetic damping coefficient is shown. The contribution of this article consists in the development and a comparison of the obtained results of three approaches for determining the magnetic damping coefficient for a mov-ing magnet in a cylindrical tube.

This document presents the characterization of the dynamic mechanical properties of a racecar's frame. First, it introduces the applicability of modal analysis, then the modal analysis of a lightweight vehicle chassis will be detailed, which is the focal point of this paper. This analysis was performed to determine some of the modal parameters, in order to reduce the noise of the vehicle, the probability of a component failure and to improve the comfort. The simulation part of the applied analysis was based on dynamic FEM (Finite Element Method). The measurement part of it was based on measuring the FRFs (Frequency Response Functions), with the help of accelerometers fixed at the nodes of the frame. The excitation signals were provided by a shaker connected to the chassis. In order to provide good quality results, the processing and evaluation of the simulated and measured data has to be done properly, which is discussed in detail. However, one dominant factor of a modal analysis is to find the optimal measurement setup. For this reason, the details of the measurement setup will be included. Hence one of the goals was to improve the coherence curves of the FRFs. Thanks to the presented techniques, the coherence curves managed to be improved and the results of the simulation and the measurement were found to be in good agreement.

Aluminum alloys are often contaminated with non-metallic inclusions. A large number of these phases accelerate the tendency of porosity in castings, significantly reduce corrosion resistance and above all affect mechanical properties. Melting is one of the conventional methods for removing inclusions from melt. The efficiency of this process is influenced by several parameters such as the chemical composition of the melt, the amount of refining substances (wire, salts, tablets), the melting point and the casting method. Therefore, an experiment was performed to evaluate the effect of PROBAT FLUSS MIKRO 100 on the structural integrity in AlSi10Mg alloy. Porosity evaluation was performed by light microscopy. To confirm the results and their reflexes into the practical production of castings, a static tensile test was performed on the cast samples directly in the foundry operation.

This paper presents a study focused on sandwich structures as well-known train construction materials that are composed of two thin and rigid face sheets and a thick, low-density core material. For trains, the wheel-rail inter-face is the main source of noise, and the wheel-rail roughness, especially in the presence of rail corrugation, is the main excitation source transmitted to the interior and area for passengers. The purpose of the study is to optimize the acoustic properties of a composite sandwich panel used for train floors and walls. Sound absorption coefficient (?), noise reduction coefficient (NRC) and Transmission loss (TL) evaluations have been implemented and experimentally validated on a typical sandwich material used for trains. The opportunity to use a different material can be concretely calculated and modified for critical frequency ranges. Sound transmission loss levels of the structural components as the floor and wall of the train body, which are required of producers and cus-tomers, were tested in acoustic laboratory and acoustic devices according to ASTM and ISO standards. It is demonstrated that, for honeycomb and cork sandwich panels, acoustic response is not sensitive to cell size. For foam core sandwich panels, it is observed that different compositions with thin layers are effective in the fre-quency range of 50 - 1000 Hz.

Q-P process is one of the latest techniques for heat treatment of high-strength steels with increased silicon levels. It is believed to be based on diffusion and migration of carbon between martensite and untransformed austenite, where the latter becomes enriched with carbon, and therefore becomes thermodynamically stable. However, the question remains whether much of the carbon partitioning in the Q-P process might be the result of the competing bainitic transformation induced by arrested quenching below the Ms temperature. This paper explores the use of dilatometry for identifying the products of austenite decomposition during Q-P processing of medium-carbon 42SiCr low-alloy steel.

If failure occurs in gear wheels in a racer motorcycle gearbox, the possible causes are manifold: inadequate material, improper care (poor lubrication, incorrect assembly) or inadequate thermochemical treatment procedure. This investigation focused on spur wheels of chromium-nickel Czech Standard (ČSN) 16720 steel containing 0.18 % C, 0.4 % Mn, 1.5 % Cr, 4.25 % Ni and 1 % W. The steel had been quenched to 60-62 HRC and the case hardening depth was 0.8 mm. The client requested that these wheels have a life of 100 hours. The failure occurred while the wheels were in operation. The fracture surfaces in the wheels were examined in a scanning electron microscope (SEM). The fracture surfaces were prominent in the failure locations. EDS point analysis in the SEM revealed spots with higher chromium levels on the fracture surfaces. The average size of these spots was several dozen micrometres. The spots were suspected to have caused or contributed to the failure. A hardness profile across one tooth was measured using a microhardness tester. In addition, the thickness of the carburized layer was determined. Quality of the surface was assessed using macrophoto-graphs taken with a low-power stereomicroscope. In addition, metallographic sections were prepared and observed in a scanning electron microscope (SEM) and light microscope.

The assessment of porosity in aluminium casting is the main object to reach the required properties. The determination of amount, size, 3D morphology of casting defect by using a non-destructive (ND) meth-od, especially the computed tomography (CT), is important for assessment casting with complex internal areas that could not be inspected by conventional measurements without failure of the final products. The aim of this study is assessment of bars casted by gravity die casting in to the sand moulds with using the computed tomography. The size, amount and volume of casting defect were assessment by equipment Zeiss Metrotom and software Metrotom OS and VG studio MAX. The results show the influence of the shape of the moulds on the quality of the bars and thus the size, amount and volume of casting defects.

Zinc-based materials are considered as promising materials for an application like biodegradable medical devices (bone fixations, stents). Such materials have to be characterized by an excellent combination of me-chanical, corrosion and biological properties. Presented paper is focused on the characterization of micro-structure and closely related mechanical properties for 3 zinc materials, namely pure Zn, Zn-0.8Mg and Zn-0.8Mg-0.2Sr. Studied alloys were prepared by gravity casting, homogenization treatment at 350 °C and extru-sion at 200 °C and extrusion ratio 11. Alloying by Mg caused the refinement of microstructure, formation of Mg2Zn11 phase and related improvement of mechanical properties like TYS and UTS for an extruded alloy. An additional encore of Sr causes a systematical improvement of TYS and UTS values, although the elonga-tion vas slightly decreased due to the presence of brittle SrZn13 phase.

Milling is one of the oldest methods of metal machining. This technology has been developed over a long time. The last milestone is the use of composite materials for the construction of cutting tools. However, there are other pos-sibilities for improvement offered by new production methods such as Metal Additive Manufacturing. The paper deals with machining experiments using a lightweight milling cutter with a lattice structure. The results of machin-ing are compared to the capabilities of a solid milling cutter. The evaluated parameters are: cutting forces, blade wear and surface roughness of the workpiece. Based on these parameters, it was not possible to confirm the benefit of the lightweight version for machining.

The presented paper deals with determination of mechanical properties of materials used for 3D printing (ABS, nylon and PLA). The theoretical part of the paper characterizes the static tensile test by which selected me-chanical properties of samples were evaluated. The practical part of the paper characterizes the additive technolo-gy Fused Deposition Modelling, by means of which standardized plastic samples were printed on the 3D printer. The practical part also deals with analysis of selected mechanical properties of samples made by Soft Tooling technolo-gy. SG 2000 and SG 145 polyurethane resins were used for the production of samples using Soft Tooling technology. Individual samples were analysed using selected tests (tensile test and hardness test). Surface integrity parameters were also determined for 3D printing test specimens. Parameters (tensile strength, tensile modulus, tensile strength and hardness) that were statistically processed were selected for each test. The paper is finished evaluating the re-sults obtained, which were compared with those given in the material sheets.

This work was focused on the research of the different variability production deep-drawing sheets made of AlMg3 alloy which could influence on their deep-drawing properties e.g. non alloying elements Fe, Mn, heat treatment parameters and structure with aim to judge ascertained and analyzed properties of the sheets. The mechanical properties, mainly the highest elongation, and the other parameters (grain size, metallurgical purity), were measured due to they had had the main influence on the deep-drawing properties of the sheets made of AlMg3 alloy. For this research work had been obtained 5 deep-drawing sheets made of AlMg3 alloy with different production than chemical composition and heat treatment with the aim to realized ?complex analyze?, and to find up the best variant for production technology with the high deep-drawing properties.

With the rapid development of modern manufacturing technology, people have higher and higher requirements for the quality of mechanical products, and the precision of machine tools for processing mechanical products has gradually increased. Therefore, the development of static pressure guides is particularly important for precision processing industries. The load on the guide rail has an important effect on the thickness of the oil film, and the stability of the oil film thickness directly determines the accuracy of processing. In order to obtain the best control method for the thickness of the oil film, the dimensions of the hydrostatic guide rails and the three-dimensional model of the guide rails were designed and calculated in this paper, and the fuel supply method of the guide rails was determined. The simulation model of the oil film was established and imported from the AMESim software into the FLUENT software to obtain the pressure, velocity, and temperature distribution maps of the oil film. And the pressure distribution data was processed after summarizing. Combined with the relevant mathematical models, the mathematical model of the oil film thickness was finally obtained. Then the Simulink software was used to analyze and the PID control was introduced for comparative analysis. The DOB anti-interference control theory was introduced, and the anti-interference control algorithm was improved. The anti-interference algorithm adapted to the oil film thickness control complete the programming of the modules of the interference controller. The anti-interference control section was created in the Simulink software, and the system of the DOB module was finally completed after packaging. In order to verify the method in t his paper, a static pressure rail test bench was set up, and relevant detection tests were completed. The results of the above studies showed that the control performance was greatly improved after introducing the anti-interference algorithm adapted to the oil film control system.

Generative design is one of the most promising means of new product development in the world. It allows formation of organic structures that brings various benefits, e.g. in the form of savings of material and production costs. Generative design includes several types of technology, topological optimization included. The paper addresses the technology of topological optimization implemented on the support part of the 3D printing pad. The result of optimization is the creation of a new, more suitable design concept through the Altair Inspire optimization software.

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.

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.

Effect of addition of cryogenic treatment to a standard heat treatment of aluminium alloy AW 7075 was tested in this work. Used heat treatment consisted of solution annealing at 470 °C for two hours and precipitation aging treatment at 130°C for 14 hours, 120 °C for 24 hours or natural aging at room temperature for 60 days. One set of samples was processed by solution annealing and aging treatment and the second set of samples incorporated 24 hours long cryogenic treatment at -185 °C between the same solution annealing and aging. Both sets of samples were characterised by tensile testing, notch impact testing, hardness measurement, microstructure analysis and wear and corrosion resistance tests. Obtained results were compared for corresponding processing with and with-out cryogenic treatment. While impact toughness and corrosion resistance were decreased by cryogenic treatment, tensile strength and wear resistance were on the other hand improved.

The experimental investigation of the vertical vibration of the vehicle is presented. The vibration of the two axles vehicle is excited by crossing of the vehicle over the transverse speed bumps on the road. The methodology is oriented upon the quarter, half and full model solution. The full geometry model is the most suitable model for the vertical vibration of the vehicle. The full geometry model is capable to describe geometric and construction asymmetry of the vehicle. The methodology of an analytical solution of the symmetry and asymmetry distribution of the vehicle and load is presented. Also, symmetric and asymmetric excitation is involved to the solution. The Heaviside?s function is applied for the excitation of vibrations. The presented methodology was applied to the experimental work with trolleybus Tr 21. The normalized speed bumps were used for the experimental setup. The vertical displacements, velocities and accelerations of axles, body of the vehicle. The acceleration of the vehicle chassis under driver seat was also recorded. This accelerations have significant effect on the comfort of driver and consequently on his/her fatigue and health condition.

This paper discusses the modeling and simulation results of a new multi-material for a cost-effective Selective Laser Sintering (SLS)-based 3D printer. As this technology utilizes several materials, the me-chanical property analysis of multi-materials is crucial for manufacturing an object with the desired physical characteristics. Firstly, the development of a database of the SLS 3D printing materials is ac-complished and based on the mechanical properties of materials, this optimization technique is proposed. Secondly, enhancement of physical property by stiffeners is considered and based on the stiffening tech-nology, and an alternative optimization method proposed. Finally, two different material minimization methods are discussed in this research. The first method is based on the embedded materials with desired mechanical properties for enhancing the mechanical properties of the printed objects, which are twice optimized by this method with increased material saving. The second method is designed to use stiffeners to improve the stiffness characteristics of the materials, and then, perform material optimization. This method is effective with more suitability to complex composite geometries. Thus, the methods help to reduce materials used as well as the production cost in 3D printing technology.

Ceramic composite materials based on boron carbide were hot pressed utilising in situ reaction of boron carbide powder with 40 wt.% of titanium dioxide sintering additive. The samples were prepared at sintering temperature of 1850 °C, pressure of 35 MPa, and time of 60 min in vacuum atmosphere of about 20 Pa. Optimisation of sintering regime concentrating on both heating stage of sintering and application of pressure enabled to prepare fully dense ceramic composite materials composed of boron carbide matrix with 29.5 vol.% of titanium diboride secondary phase. The ceramic composite reached average density of 99.3 %, hardness of 29.8 GPa, and fracture toughness of 6.9 MPa.m1/2.

This paper describes a search for an optimal organization of the drying agent motion in the convection dryers. An overview of the main methods on how to reduce the energy consumption for the convection drying of the disperse materials is presented. The use of the multistage shelf apparatuses with a differential thermal regime for the con-vection drying of the disperse materials is justified. The work contains the results of a computer modeling on de-termining the drying temperature and moisture characteristics with the use of various methods of the organization of the drying agent motion. The model is realized implementing the author?s software product Multistage Fluidiz-er?. The software product enables to automatize calculation simultaneously by several optimization criteria and to visualize calculation results in the form of 3D images. The engineering computation of sectioning devices meth-odology with fluidized bed of particles is based on the calculation results. The automated calculations results give a base to design industrial drying device with a differential thermal regime.

The article presents the results of theoretical research on creating the mobile continuous earthmoving machinery. The aim of the article is to develop and evaluate the effectiveness of technical decisions when creating and mod-ernizing trencher chain and bar actuators. The peculiarity of the performed research is a complex way to solve the problems of ensuring the efficient operation of the earthmoving machinery. It involves a combination of two subsystems: "soil - operating equipment" and "basic chassis ? bearing capacity of soil surface". The mechanisms of changing the power parameters of the machinery load are established. The input parameters for a system de-scribing the operation of a special earthmoving machinery are soil physical and mechanical characteristics and the dimensions of the earth excavation, the installed power of the basic chassis engine, the type and characteristics of transmissions of the machinery operating equipment and chassis propulsion, geometric parameters of single cutters, the speed of cutting the soil and moving the machinery. The mathematical model of the system as a whole makes it possible to determine the rational design, kinematic and energy characteristics of the machinery and its operating equipment. It minimizes the energy intensity of soil development.

The article deals with analytical and experimental solution of vertical oscillations of a mechanical system of bound bodies. The content of the article is to perform an analytical solution of the vertical oscillation of a system of bodies using the computer program MathWorks Matlab and MS Excel. Furthermore, an experimental investigation on a laboratory model of a mechanical system of the same parameters was proved. The aim of the work was to compare the analytical solution with the experimental method and to check the accuracy and applicability of analytical methods for the solved mechanical system.

The subject of the article is a comparison of new and used powder for 3D metal printing. The powder is 316L stainless steel manufactured by Renishaw. The powder used was taken from the RENISHAW AM250 printer after use. Powder manufacturer Renishaw recommends using 15-45 micron powder in their 3D metal printers. An im-portant parameter of monitoring is the chemical composition of the metal powder and its changes during the thermal treatment during laser sintering. Another important parameter of a metal powder is its mechanical prop-erties, which determine the flowability, consistency and uniformity of powder application. By using an inert at-mosphere for sintering and storing the powder, these chemical changes can be prevented, especially against the formation of nitrides and oxides at elevated temperatures.

Small holes can be manufactured by several ways. It is important to define in what dimensions the small holes vary. Anyway, drilling is one of the oldest technologies of holes manufacturing. In small dimensions we use the term microdrilling for description. Beside this conventional way of manufacture there are also unconventional methods. Microdrilling bits very often break before they are worn. Therefore, the tool life of these bits its quite unexpectable. It is due to relatively high load against the drill bit strength. So, it is important to choose proper drill bit material, cutting geometry, construction, process liquid, clamping and cutting conditions. These parameters are import for achieving ideal conditions for microdrilling. Even a tiny change in pre-seted parameters can lead to destruction of these delicate tools. Fiber arrays are designed and manufactured for precise positioning of optical fibers in row (1D) or in plate (2D). Fiber arrays can contain most of fibers including polarization maintaining fibers (PMF).

Scratching force is a significant factor to evaluate the characteristics of single diamond grit scratching process. In this paper, experimental study was carried out to investigate the vibration characteristics of force signals during the scratching process. A precise multicomponent dynamometer is employed in the force measurement during a single diamond grit scratching on pure copper. The frequencies of the vibration section of force signals with different scratching parameters are calculated and analyzed. The influence of force signal vibration on the measuring accuracy of dynamometer is systematically analyzed further. The results show that higher scratching speed and larger scratching depth lead to larger vibration amplitudes of the force signals. Strong impact on the quartz piezoelectric crystal of dynamometer, which is produced indirectly by single diamond grit scratching process, leads to the vibration of scratching force signal. The first semi-sinusoidal force signal is the actual scratching force. The vibration of the scratching force signal has little effect on the measuring accuracy of the dynamometer.

The paper deals with dynamic in-plane simulation analysis of a motorcycle suspension. The motorcy-cle᾿s mechanical model is considered as a visco-elastically suspended rigid body. Two types of the kinematic excitation are considered ‒ a deterministic „hat“ shaped bump and stochastically uneven road characterized by its power spectral density. The simulation results for both the deterministic bump and stochastically uneven road show that significant reduction of the root mean square value of the motorcycle body centroid acceleration (comfort criterion) can be achieved by placing the lower end point of the rare spring-damper module closer to the beginning of the swinging arm and also by increasing deviation (tilt) of the spring-damper module from the vertical. The maximum improvement in the root mean square value of the motorcycle body centroid acceleration is 51.7 % for the deterministic „hat“ shaped bump and 37.4 % for the stochastically uneven road. The method presented in the paper can be employed in design of both touring motorcycles, which are characterized by higher requirements of comfort, and off-road motorcycles where protection from impacts generated by bumps is important.

The 54SiCr6 steel belongs to spring steels which excel high strength and at the same time reaches high values of reduction of area and sufficient value of elongation. Nowadays, new methods are searched and examined how to get better properties from materials, higher strength and toughness, longer fatigue resistance or better corrosion properties. In the case of silicon-chromium spring steels, innovative heat treatments are investigated such as quenching and partitioning which enables to achieve higher ductility of steel due to higher content of retained austenite. The way of modification of the chemical composition of the 54SiCr6 steel was chosen in combination with conventional heat treatment composed of quenching and tempering to get better properties. The materials with in-creased content of copper to 1.5 wt. % and silicon to 2.5 wt. % were prepared. The influence of alloy-ing elements on microstructure and mechanical properties was followed up to the tempering temper-ature of 400 °C.

The magnesium alloys, alloyed by the low amount of calcium and zinc concurrently, are considered as a biodegradable materials for implants. However, the as-cast alloy exhibits the insufficient mechanical properties as well as corrosion resistance which are affected mainly by the presence of brittle secondary phases, such as Mg2Ca. For this reason, presented work was focused on the as-cast magnesium alloy with alloying elements (Ca and Zn) whose content did not exceed 1 wt. %, specifically MgCa0.5Zn0.5 (in wt. %). Microstructure consisted of magnesium matrix with a very low amount of Mg2Ca and Ca2Mg6Zn3 phases which crystallized along the boundaries. These phases and their localization influenced the resulted mechanical properties. The hardness was higher due to them and tensile properties were worse than the compressive ones. The addition of zinc did not improve ductility, but in the case of compressive stress-strain test, the relative deformation was satisfactory. Moreover, the corrosion resistance of as-cast alloy MgCa0.5Zn0.5 was better than pure magnesium.

Colour metallography, especially colour etching, is a widely used technique for visualizing different phases in the structure of metals. Its advantage to the traditional etching techniques is that it gives additional information about the structure of material. The paper deals with the structural analysis of graphitic cast irons with a focus on colour etching. The possibilities of extending information about the structure of cast irons using colour contrast compared to classic black-and-white contrast is discussed. The paper is supplemented by photographs of microstructures of graphitic cast irons, obtained using classic black-and-white methods, as well as colour etching. Colour photographs of the structure of cast irons were obtained using the light metallographic microscope Neophot 32 with a digital camera Nikon DS-Fi3. Selected etchants for traditional black-and-white etching and for colour etching were used.