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Adhesion of resins and adhesives to adherend is one of the important characteristics, including the area where the resin or adhesive is filled with particulate fillers in order to optimize this adhesion, achieve other mechanical characteristics or in order to reduce the price of the resulting resin or adhesive. When discussing filled resins with particulate fillers, these materials can be defined as a polymer composite systems. Surface treatment of adherend before applying such a filled resin, is crucial to the overall strength of this interface. Blasting is commonly used kind of surface treatment of metal adherends. Properly chosen blasting conditions and achieved roughness parameters are crucial to the overall strength. The experiment describes the impact of the changing conditions of blasting on the shear strength of epoxy resins filled with glass powder. The results of the experiment show that the highest shear strength on steel adherend was achieved when the surface was blasted at an angle of 60 - 90° (12.93 ± 0.62 MPa). The roughness parameters Ra and Rz were influenced by a specific kind of blasting material (Al2O3 F80 and glass beads B10), which has also a considerable influence on shear strength.

We can define wear as a phenomenon, which humanity can't fully explain and many do not understand it well. It is known for several millennia. It's an action, which can't be avoided. Often it's a critical factor affecting lifetime of device parts, for example the wear of plain bearings in many rotational devices can affect the function and cause great damage to it. The presented paper deals with stress and contact pressure distribution simulated by the finite element method (FEM) and the development of a wear module for simulating sliding wear of materials. First the theory of wear is presented. The next section presents the development of an own wear module in MATLAB, which also deals as an interface between MATLAB and ABAQUS software. Finally the module is tested on a sliding wear testing problem which is simulated using ABAQUS and the simulation results are presented at the end.

The current mechanical engineering is inconceivable without the implementation of CAx systems in design and manufacturing process of individual components. The automotive industry is a clear evidence of how CAx systems affect the innovation cycle of its product - a car. The innovation cycle in automotive was reduced from 8-12 years to the current 4-6 years. Even in this short interval automakers make some small design modifications called a facelift. Development in the automotive industry, therefore, is closely related to news and functionality CAx systems. CAD systems at the turn of the millennium are characterized as parametric graphic systems with a history tree of product creation. Parametric design implemented into CAD systems makes the model variable and open to rapid change management. The history tree in turn enables rapid editing and modification of forming or editing functions.

Piping systems of boilers are mainly exposed by high temperatures, pressures and corrosive loads. This corresponds to the choice of materials boiler pipeline. These materials are in most cases special stainless steel for energetic equipment. Article deals with the evaluation of the resulting degradation of thermally stressed pipe boiler, which occurred after the increase boiler capacity. Degradation showed an increased amount of corrosion products on the inner surface of the pipeline, which resulted in clogging of pipes, formation of cracks and leakage of steam. Complex analysis was carried out of corrosion products and material microstructure pipelines. The result was that occurred to intergranular corrosion of pipelines in loaded state. On the basis of this was carried out analysis of the material in the unloaded state. Chemical composition and microstructure correspond to prescribed standards and requirements. Test of resistance to intergranular corrosion revealed that in the steel causing damage to the cohesion of the material along grain boundaries. It is for this type of material inadmissible. Therefore it is necessary in the case of increasing the performance of the boiler and thus the increase in temperature and pressure, to ensure a higher resistance to intergranular corrosion of the material.

3D printing technology has recently extended to metallic materials and allows now to produce 3D models directly from metallic powders. There are several methods of 3D metal printing, such as Selective Laser Sintering (SLS), Direct Metal Laser Sintering (DMLS), Electron beam melting (EBM) or Selective laser melting (SLM). Compared to conventional technologies of casting, forging and machining, these methods offer many advantages. The most important is shape variety allowing preparation of very complicated shapes and designs, which would be impossible to reach by classical techniques. Moreover, there is practically no material loss, since the remaining powder can be recycled and reused in other manufacturing processes. That is one of important cost savings. However, for now, the metal 3D printing is unable to compete the price of large-lot production. In present paper, it is demonstrated that by the SLM technology it is possible to achieve comparable material properties of stainless steel AISI 316L as by conventional technologies and therefore, this method offers a suitable alternative.

An article deals with a concept of increasing efficiency of a current production process of bearing ring machining. A goal is to substitute a generally expensive technology of cutting when at least the same integrity of a surface is kept. A theoretical part is focused on a characteristic and analysis of a given component including an applied material 100Cr6 from which bearing rings are made. A practical part analyses and suggests an innovation of increasing efficiency of the machining process. Series of samples would be tested experimentally at university conditions (Workroom C2 of Dept. of Machining Technology, Faculty of Mechanical Engineering, Brno University of Technology) using CNC Lathe Machine SP 280 SY.
The article describes individual production workplaces along with used tool equipment that includes for the process of increasing efficiency the innovation in the form of the change of the production process, changes of most cutting tools and cutting conditions needed for the turning of heat-treated bearing rings. The article also deals with a surface integrity after turning of bearing rings. The integrity is analysed using a touch measuring tools (a manual roughness tester TS100, a tool with an inductive sensor Form Talysurf Intra) and using a touchless measuring tool Alicona Infinite Forces G4, including the measurement of a residual tension in a surface layer (Barkhausen noise) by the tool Rollscan 300.
The article finishes with a wear test of replaceable cutting blades at applied cutting conditions with a follow-up discussion, which describes problematic steps that were done in particular phases of experimental testing, and with necessary concept of further testing of bearing rings.

Pherrography uses microscopic methods for the detection of morphological characteristics of wear particles deposited on pherrogram. The result of pherrographical analysis is to create the pherrographic track on pherrogram and then to assign the type and intensity of wear. The position of nonferrous metals on the pherrogram is quite clearly defined. Assessment of particle size, particle shape and distinguishing kinds of material are the result of observation. Nonferrous particles are also divided according to the color. Metal particles can, under certain circumstances, have different colors as a result of excessive oxidation of the particle surface. The article deals with the identification of nonferrous particles on pherrographical track of motor oil. This assessment is carried out in relation to the mode of wear of oil and machine. Part of the experiments is also microchemical analysis for subsequent analysis of certain hard identifiable metals.

NiTi alloy is characterized by many interesting properties assiciated with the shape memory behaviour. Since this material can be superelastic and recover the shape after deformation, it can be considered as potential matrix for composites. In this work, the possibility of preparation of NiTi matrix composites was tested. Two kinds of materials were studied - NiTi matrix composite reinforced by ceramic particles and in-situ composite containing NiTi and hard Ti2Ni phase obtained by reactive sintering of Ni+Ti mixture.

Aluminium is among the materials that found their application in composite systems. Aluminium matrix composites may form or may be present in the matrix in the form of fillers. Specific applications of aluminium may be present in the epoxy or other polymer matrices in the form of microparticles. Mutual interaction of resin and aluminium particles then creates the resulting properties of the material, which can be used both for surface treatment, and in the bonding and sealing. For this reason, adhesion and cohesion characteristics are among the leading characteristics of such systems. The paper describes cohesive characteristics of two-component epoxy resin filled with microparticles of 30.44 μm. The presence of particles changed tensile strength of resins from the value 49 MPa 30 MPa. The adhesion characteristics were evaluated on both aluminium and steel adherends. The presence of low concentrations of microparticles of aluminum, i.e. to 8% did not result to the statistically significant decrease of values of the shear strength of resin at both, aluminum and steel adherends.

The paper deals with the current topic of environmental taxes on the level of the Czech Republic. The urgency of the topic is highlighted by the dynamic international development of environmental taxation and continuous unification within the European Union. Environmental taxes affect the final consumers of solid fuels, electricity and natural gas and some other gases. The paper researches the impact of environmental taxes on a selected group of manufacturing business entities which are largely consumers of products taxed by environmental taxes. This type of taxes represents a part of corporate environmental costs and as such it is necessary to manage these costs. At first the paper examines the influence of environmental taxes on the enterprise performance after their introduction into the Czech tax system in 2008 and then there are proposed the indicators for monitoring and management of environmental taxes as a part of the enterprise costs. The influence of environmental taxes on business entities is researched by the profit and loss report item "consumption of material and energy", the economic result, rentability of assets indicator and also by the proposed material and energy costs rentability indicator. Further there are proposed two other ratio indicators for environmental taxes monitoring within the corporate costs which can also serve as one of the criteria for investment decision-making of an enterprise. For the correct quantification of the proposed indicators a reference accounting timetable is drafted which includes the environmental taxes analytical evidence and their integration into the corporate accounting.

The aim of the article is to present suitable changes at the conception of the angle of attack setting mechanism and the modification of the spring element at the load module SIMRAIL, part of roller rig RAILBCOT which faithfully simulates the behavior of the vehicle on a real track. RAILBCOT is the acronym for RAIL vehicles Brake COmponents Test stand. During the measurements were recorded imperfections, which could influence continuous testing, and would lead not to reliable and fully trusworthy results. The article describes three steps to improve the situation. The first step describes the stabilization of the members to prevent the occurrence of clearance. In the second step were started measurements at the roller rig at different operating speeds. In the third step is modified the angle of attack setting mechanism where was mechanical spring element changed by hydraulic spring element. Mentioned is also the need for increasing the stiffness of the spring element, which lack of stiffness caused loss of stability before the requesting speed. Modified was the gear lever, where was changed the transmission ratio and dimensioning of spring element.

This paper reports on doping with the catalysts consist of rare metal compounds like Co₂B, La(NO₃)₃, Ce(SO₄)₂, Ti(SO₄)₂, CeCl₃, LaCl₃ and mixed catalysts for improving hydrogen release capacity of NaBH₄. The results show that the hydrogen generation volume (HGV) is about 10ml and the hydrogen generation rate (HGR) is very low when doping with La(NO₃)₃, Ce(SO₄)₂, Ti(SO₄)₂, CeCl₃ and LaCl₃. Comparatively, Co₂B presents favorable catalytic effect on hydrogen generation properties of NaBH₄. The study on the mixed catalysts find that the HGV of the samples doped with mixed catalyst of Co₂B and Ce(SO₄)₂ is the largest. Among all doped samples, the HGV of sample doped with 5Co₂B\2Ce(SO₄)₂ is the largest about 317ml. Compared to all samples doped with mixed catalysts, the samples doped with mixed catalysts of Co₂B, Ce(SO₄)₂, Ti(SO₄)₂ and CeCl₃ presents the best properties of hydrogen release. However, compared to Co₂B, doping with other catalysts makes the hydrogen release time of NaBH₄ longer. Overall, NaBH₄ doped with the mixed catalysts of Co₂B, Ti(SO₄)₂ and CeCl₃ present the optimal HGV and HGR than doped with any other catalysts.

The ultrasonic/ceramic membrane combined process was employed to have a better effect of the filtrated water quality. We set the ultrasonic frequency at 20 kHz and the corresponding power at 2kW. Innovatively we probed into different range of molar weight of organic matters in the filtrated water, and results showed that the ultrasonic/ceramic membrane combined process could change the distribution of micromolecule organic matters. We found that with the increasing of turbidity of raw water, the membrane flux decreased rapidly but the quality of filtrated water changed little. Studies on different range of molar weight showed that for the organic matters whose molar weight were below 1kD, higher turbidity had an optimistic effect on removing them while for those whose molar weight were above 1kD, the effect was reverse.

Beside cutting speed, shift is another important parameter of machining. Its considerable influence is shown mainly in the workpiece machined surface microgeometry. In practice, mainly its combination with the radius of cutting tool tip rounding is used. Options to further increase machining productivity and machined surface quality are hidden in this approach. The paper presents variations of the design of productive cutting tools for lathe work and milling on the base of the use of the laws of the relationship among the highest reached uneveness of machined surface, tool tip radius and shift.

In the field of designing of new or renovating the existing rail vehicles the iussue of individual structural units lifetime is currently appears increasingly coming to the fore for the vehicles long-term operation. On one hand, modern tools of virtual reality allow performing stress analysis of structures, most frequently using FEM, on the other hand, there is software designed for multibody system assembly intended for the evaluation of rail vehicles dynamic properties. Flexible bodies' implementation into a rail vehicle multibody system considerably extends the possibilities of computer simulations of rail vehicles running. In this paper we present inclusion of a flexible body into a multibody system of a rail vehicle bogie. We chose a freight wagon bogie for the purposes of modelling and simulation. Parameters of the fright wagon correspond to a Y25 bogie. Simulation calculation of the bogie running on the track have been performed using a track model consisting of two reverse curves.

The paper describes the flow measurement in an aneurysm model by PIV (Particle Image Velocimetry) and PLIF (Planar Laser Induced Fluorescence) method. The velocity field and the concentration were determined for four steady and one unsteady flow regimes.
The area of the main flow and the area of liquid circulation in the region of the bulge were defined on the basis of velocity field measurement. Mean concentration of dye was evaluated in three areas: the entry to the model, the bulge of aneurysm and the outlet of the model. Concentration in course of time and residence time of dye are discussed on the dependance of unsteady flow.

Direct Metal Laser Sintering enables production of fully dense metal parts with comparable or higher tensile properties as compared to the conventionally produced parts. However, for a more widespread use of this additive manufacturing technique, material data should be obtained and evaluated with respect to the influencing manufacturing factors. In the case of Ti6Al4V alloy, the fatigue performance can be highly susceptible to the process related issues, such as build direction, porosity and surface condition. This study was undertaken to examine the fatigue life of Ti6Al4V specimens manufactured by Direct Metal Laser Sintering (DMLS) technique and to investigate the influence of the surface state on the fatigue life. A high degree of anisotropy in the fatigue performance associated with the specimen build orientation was determined.

Nanomaterials are advanced materials exhibiting unique mechanical, chemical and physical properties due to their structural constituents having size less than 100 nm. Such materials are suitable for using in wide field of possible applications e.g. special structural applications, catalysis, biomedicine or electronics. There are many methods how to produce nanocrystalline materials or nanoparticles including vapor, liquid and solid processing routes. In this work, ultra-high-strength nanocrystalline silver was prepared by combination of selective leaching and subsequent consolidation by spark plasma sintering. Conventional cast silver was used as reference materials.

At present commonly used conventional materials are substituted by materials of better mechanical qualities. For example highly alloyed steels with chromium, cobalt and nickel alloys, titanium and titanium alloys belong to this group. Titanium and its alloys also belong to the group of hardly machinable materials thanks to its good chemical and physical properties, such as high strength, high corrosion resistance, low density, deformation resistance at high temperature and at the same time low thermal conductivity that unfavourably affects the process of machining. Despite its more complicated machining, titanium together with its alloys are widely used in the aerospace, aviation and automotive industries and, last but not least, in biomedicine. Biologically compatible materials are used for production of implants in medicine from comercially pure titanium TiGr2, TiGr5, nanostructured commercially pure titanium nTI and titanium alloys TiNbTa. As there is a need to produce still smaller and more complex implant with extraordinary accuracies, there arises a strong necessity to understand the process of their machining. We have already published experimentally gained knowledge on turning and milling of stated materials. In this paper we aim to inform about machinability of these materials in drilling.

The article deals with mechanical properties of plasma nitrided steel. Experimental work was focused on evaluation of influence of plasma nitriding process to notch toughness of steel, the experimental were realised on V-notch samples of size 10x10x55 mm (according to CSN ISO 148-1 standard). Nitrided layers were applied to steel 30CrMoV9 which were subsequently evaluated by metallographic, GDOES and microhardness method. The notch toughness tests of steel were carried out using the instrumental Charpy hammer at temperatures -40 °C, +21 °C and + 70 °C. The results of experiments showed that plasma nitriding process has a direct impact on change of notch toughness parameters. The notch toughness of plasma nitrided steel was significantly decreased. The measurements thereinafter showed that values of notch toughness at low temperature (-40 °C) decreased but also at higher temperature (+70 °C). It was found a dependence of notch toughness values of plasma nitrided steel between the testing temperature and plasma nitriding process parameters.

This contribution describes the progress of wear and influences contributing to wear of a cutting tool during straightturning of the Nickel superalloy Inconel 718 according to W. Nr 2.4668. According to the ISO 513 standard this alloy belongs among heat resistant materials; it is a special Nickel alloy used primarily for machine parts in the aircraft industry. The experimental part was done for the purpose of testing suitability of proposed exchangeable cutting inserts intended for machining of Inconel 718. Mechanisms and magnitude of wear and durability of the tools were determined in accordance with the ISO 3685:1993 standard in order to evaluate suitability of the proposed tools.

The CT-conveyed hydrajet perforating and annular-delivery sand fracturing in horizontal well can meet the requirements of large-scale stimulated reservoir volume and separate-layer multistage fracturing. So it is always as an effective technique to stimulate low and ultra-low permeability reservoirs. Unfortunately,in the process of annular-delivery sanding fracturing, the CT will endures a larger piston force, the accuracy of fractured intervals and the security of fracturing string can't be guaranteed. In this paper, with the method of mechanical analysis on horizontal CT and numerical simulation on packer's anchorage force, we obtain the effect of CT pump rate on its stress: When CT pump rate is smaller, the maximum axial and Von Mises stress happen at the CT bottom, where there exists a risk of strength failure; As CT pump rate increases, axial stress and Von Mises stress decreases gradually; The maximum safety factor can be obtained at the CT critical pump rate. Therefore, for annular-delivery sand fracturing, we'd better insure CT pump rate more than the critical value.

ŠKODA VÝZKUM cooperated on the development of the NEOPLAN DMA low-floor articulated trolleybus intended for the Boston city (the United States). Multibody models and finite element models of the trolleybus were utilized in the stage of the vehicle design. The multibody models of the trolleybus were created in the alaska simulation tool and the simulations were especially aimed at determining forces acting in the trolleybus suspension elements and radius rods. At the end of the stage of computer modelling and testing the trolleybus prototype a decision to change the type of shock absorbers used in the axles' suspension was made. The impact of this change on forces acting in the trolleybus suspension elements (i.e. in air springs and shock absorbers) and radius rods on the trolleybus chassis when running on an uneven test track was investigated using multibody simulations. Time histories of the forces calculated utilising multibody models were used as input data of the trolleybus finite element models. Stress in the critical places of the trolleybus body structure was determined utilizing the finite element models.

Aluminium alloys with higher content of alloying elements are very susceptible to the emergence of crystal segregation that significantly affects the mechanical, physical and chemical properties of these alloys. Crystal segregation is called chemical heterogeneity in microscale and is formed during crystallization. Crystallization of alloys does not occur at a particular temperature, as is the case of pure metals, but in a certain temperature interval. During cooling of the melt occurs to formation of different regions within the dendritic cell that differs in chemical composition. Generally is crystal segregation defined as chemical heterogeneity formed during alloy crystallization that is enriched or deprived of alloying elements and impurities that segregate unevenly across the surface of the dendrites. In the central area of the dendritic cells is alloy deprived of alloying elements, while the outer parts of dendritic cells and in space between dendrites is the concentration of alloying elements richer. This concentration has a hyperbolic course, when the central region of dendritic cells has the lowest concentration of the alloying elements and the outer part of dendrite boughs and interdendritic space have the maximum. Distribution of individual elements has a recurring character and can be described by sine function. The distance between two main axes of dendritic cells is affected by the temperature interval between the liquidus and solidus for the given alloy, the cooling rate of the melt and temperature gradient during solidification. Formation of the crystal segregation in aluminium alloys rich in alloying element and additives cannot be prevented, it is possible only influence its scope and with the right choice of heat treatment parameters can be suppressed. To suppress the crystal segregation the castings are subjected to heat treatment which is called homogenization annealing. It is the diffusion process in which there occurs to a balancing of chemical composition of alloy and the uniformity of its structure.

The article deals with the analysis of axisymmetric flow field from the point of view of vortex identification. The vortex is identified by using residual vorticity defined in the work [1]. The identification is based on the so called triple decomposition of motion [1]. The idea of vortex identification based on the residual vorticity which is easily applicable in the case of two dimensional flow field is extended to the case of axisymmetric flow. The analyses is based on the decomposition of velocity gradient tensor and on the search of so called basic reference frame which allows to examine clearly the kinematics of the flow field.

The paper present the structural design of freight wagon chassis frame with adaptable loading platform with regard to the safe operation and assessment of the properties by the calculation methods of simulation analysis. 3D model of wagon was created in a computer program PTC/Creo. Wagon chassis frame was subjected to the static and dynamic analysis in programs ANSYS and ADAMS/Rail. On the basis of computer aided simulation analysis was optimized the frame of the wagon. This wagon chassis frame will be able to offer even more capacity and utilize less resources and energy than current wagons for intermodal transport.

The most widely used technologies of founding Al-Si cast alloys are gravitation and semi-centrifugal casting, casting under pressure and so on. The contribution deals with influence of different casting method on changes of Fe intermetallic phases. Casting into metallic mould and sand mould were used for experimental work for comparison Fe-rich formation. Fe is a common impurity that leads to the formation of complex Fe-rich intermetallic phases. The dominant phase is plate-shaped Al5FeSi. These phases are unwaited, because reduce properties of aluminium casting. The experimental materials have most common addition Mn. The addition of Mn may reduce Al5FeSi phase and promote formation Fe-rich phases Al15(FeMn)3Si2 in "skeleton like" or "Chinese script" form. This knowledge was confirmed. The present study is a part of larger research project.

Manufactures of automotive engines and complete vehicles strive for the lowest possible fuel consumption, which also leads to the use of motor oils with lower viscosity. Lower viscosity of oil reduces internal friction and provides faster distribution of oil into lubrication points, but simultaneously reduces the size of transmitted power. The design of automotive engines use plain bearings, which are based on aluminium, brass. Further are used steels with coating based on aluminium and bronze. The paper describes the impact of viscosity of motor oil to wear of basic materials, which are used in production of plain bearing. Reichert tester M2 for evaluation the lubricity from Petrotest Company was used in order to assess ability of motor oils to create proper lubricating film. Reichert tester M2 belongs to a group of equipments simulating real frictional contact. Stabinger viscometer was also used for the precise determination of viscosity of various types of motor oils.

Laser Shock Processing (LSP), or strengthening the material surface by laser shock wave is very modern and progressive technique, which allows a significant increase in fatigue life of cyclically loaded parts. The compressive residual stresses are generated in the surface layer of material processed by laser beam, which can significantly improve the fatigue properties of the material and reduce the initiation and propagation of the surface cracks. This technique finds practical use of the most demanding applications like in the aerospace industry. For this reason, we are mapping the selected surface properties after the laser treatment for the better understaning of technology possibilities. After that another suitable applications can be found. It is also important to determine appropriate parameters for different types of material and requirements affecting the result.

Weapons are special systems, which have high demand in terms of reliability, safety and durability especially in the case of automatic weapons. The most stressed parts of weapons are barrels, breech, locking elements etc. This paper si focused on the failure of locking element, which is used for set the breech baffle and for locking of the breech. From the structural point of view the locking element is highly dynamically stressed component. During the shooting cycles are the shocks transferred into these components, therefore specified material requirements of the locking element are needed. The material of locking element must be modified to hard surface with tough core with thickness corresponding to the size and frequency of shocks to prevent the fatigue failure. The manufacturing documentation wasn't available, therefore the chemical analysis was performed using the GDOES/Bulk method. The results were compared with material standards to determine the Czech steel equivalent. The damaged locking element was metallographically tested, the surface and microhardness testing was performed by Vickers method. The fracture surface morphology was using the light and electron microscopy (SEM) observed.