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Quality design is necessary prerequisite for correct and safe operation of all mechanical devices. This design has to consider all simulations and calculations. All boundary conditions have to be involved in this design. Ignorance of some of them can lead to overloading of structure or to the destruction of whole device, as shown in the example in this paper. Following design solutions can improve these mistakes, but this is technically difficult and costs are much higher. This article deals with calculations of air piping and with supporting structures for this system. This example from praxis shows importance both simple calculations and advanced structural simulations. Benefits of advanced FEM simulations are shown clearly using described structure. These benefits can be applied on all mechanical systems.

This article offers completely new results in the research of NiTi alloys produced by Self-propagating High-temperature Synthesis (SHS). There is investigated the effect of addition of magnesium on the microstructure, phase composition and especially, the amount of undesirable Ti2Ni phase. This phase is unwanted in NiTi alloy because of its brittleness. Moreover, this one is stabilized by oxygen and forms during SHS process. Selected preparation method is considered as an alternative to the melting metallurgy, which produced products with poor homogeneity and purity. For this reason, SHS process has been studied intensely and many researchers have tried to eliminate secondary phases unsuccessfully. Our research showed that alloying by element with high affinity to oxygen causes disappearance of Ti2Ni phase.

The submitted paper presents possibilities of a simulation for a real manufacturing process in a company taking the risks into consideration. The risks may result from various sources in manufacturing environment. The most significant ones include a human factor, the processes in general and environs where the manufacturing process takes place. Risk can be viewed as a state where there is a possibility of a loss but also a hope of gain since one would never jeopardize the loss if there were no chance of a win. Because of the argument that a risk is perceived differently depending on the observer's experiences and objectives, it has become increasingly important in organisations to create awareness and gain information of potential risks. The paper is aiming to present the possibilities how to avoid such risks or to decrease them to an acceptable level through simulation and modelling tools.

Comprehensively considering the analysis results of the microstructure, hardness and tensile properties, different zones of a component for aircraft applications manufactured through hot stretch forming were studied. The differential thermomechanical story of each studied zone of the forging was taken into account. The results reveal that the different zones strain hardened in function of the degree of the strain and strain rate experienced during the forming, with the zones most stressed at the higher strain rate showing the best tensile properties and a loss of ductility. This phenomenon is not coupled with a visible change into the microstructure morphology of the processed material.

An article deals with a definition, concept, development, calculation and construction of a prototype of mechanical regulation of a turbine ventilator using a whirling turbine reducing an amount of ventilated air.
The whole mechanical regulation solution is situated at a central shaft with arms. At low air velocity, a rotation nozzle is pulled out fully from its cover and works with a maximum suction capacity. The rotation nozzle starts to pull in its cover at higher air velocity, which protects the blades from push of air, which would slow down the whole turbine. A vertical move of the turbine is provided by an inner mechanism functioning basically as a centrifugal regulator. The advantage of this concept lies in not only suction regulation, but also protection of the rotation nozzle from a damage in case of adverse weather (the rotation nozzle stays inserted). The article describes individual development stages from a concept up to construction, including the final visualisation of the prototype solution of the mechanical regulation of the turbine ventilator using the whirling turbine.
The mentioned innovative solution of the mechanical regulation is very up-to-date thanks to its simplicity and nonservice operation. It is just the matter of time when one of the producers would be interested in the turbine ventilator solution and it would be introduced into a market space.

The article deals with the wave propagation in thin plate. A wave was caused by the impact force. In the first part of an article the Kirchhoff's theory of thin isotropic plate is given. It is a vertical displacement w, angles of rotation tangent φx and φy, bending stresses σx, σy, shear strength τyx = τyx, shear strength from displacement forces τxz, τyz. In the second part of an article is solved a Kirchhoff's theory by analytically in MATLAB programme. Analytically were solved only displacements u, v and velocity u ̇,v̇ . The solution is performed for two plate materials - aluminium and steel. By result are deformations and velocities graphs in the x-axis and the y-axis at the measurements points given. In the conclusion of an article is comparing of individual deformations and velocities graphs.

Cutting tools made of cemented carbides currently dominate the field of machining. This is due to their outstanding properties and applicability to various materials. However, there are still opportunities for enhancement in the field of cutting tool durability, particularly in the machining of highly resistant super alloys. Grinding critically affects the integrity of the machined surface, which has a significant impact on the durability of cutting tools. Certain cutting conditions and grinding strategies can lead to a sudden failure of the cutting tool in the cut. The main goal of this study is to investigate the influence of the cutting conditions on the end mill flute surface quality and durability of these cutting tools when machining Inconel 718. The surface parameters are described and real machining tests are conducted.

The microstructure and mechanical properties of carbon fibers reinforced EN AW 6082 aluminium matrix composites after hot extrusion were investigated. The distribution of carbon fibers in matrix was homogenous and their alignment was in the extruded direction. The microstructure of aluminium matrix alloy in the composites was fine grained, without defects. The heat treatment (annealing at 550 °C for 1 hour, water quenching and artificial aging at 170 °C for 8 hours) caused formation of fine solid solution grains of aluminium alloy and dissolution of Mg2Si particles. The highest value of ultimate tensile strength was achieved in composite reinforced with 10 vol. % of carbon fibers, the worst value was achieved in composite reinforced with 20 vol. % of reinforcement. The application of heat treatment led to an increase of 0.2 yield strength and the ultimate tensile strength of composites compared to extruded states in all types of materials. These changes caused precipitation of β''- phase particles.

When constructing traffic means, agricultural machines etc. it is necessary to create a bond, namely from thin semi-products, i.e. sheets of metal. Namely light and strong materials such as e.g. aluminium alloys EN AW 2024 T3 (AlCu4Mgl) are used in the constructions. A research namely on the adhesive bonded surface treatment is necessary at a rise of the quality adhesive bond. The aim of the research is an evaluation of the adhesive bonded surface treatment of the aluminium alloy EN AW 2024 T3 (AlCu4Mg1) by means of mechanical tests and a surface analysis by means of SEM. A cyclic degradation loading of the adhesive bond after exposing the adhesive bonds to increased and decreased temperatures, i.e. in the interval -40 to 70 °C in a programmable climatic chamber MKF240 and connected adhesive bonded surface treatments were evaluated within the research. The adhesive bonded surface treatment was of the positive influence on the strength and the elongation of the adhesive bond and it increased the resistance to the cyclic acting of the degradation environment at the same time.

An important factor in enhancing the mechanical properties of high-strength steels is the stabilization of an appropriate amount of metastable retained austenite in martensitic matrix. Various novel heat treatment and thermomechanical processing routes have been developed recently which benefit from the effects of retained austenite in terms of achieving better elongation at still high ultimate strength levels. One of these procedures is the Q&P process (Quenching and Partitioning). It produces martensite and retained austenite to obtain strengths of more than 2000 MPa and elongation levels of about 10%. For this investigation, four steels with low Ms temperatures have been selected. Their chemistries contained manganese, silicon, molybdenum and chromium.The development of heat treatment sequences involved trials with various austenitizing temperatures, cooling rates, quenching temperatures, and carbon partitioning temperatures for the stage in which austenite becomes stabilized. The experimental heat treatment led to microstructures consisting of martensite with retained austenite in all the steels. Their strengths were in the range of 1750-2400 MPa and their A5mm elongation was 10-15 %. The largest fraction of retained austenite, according to X-ray diffraction, was 10 %. Specimens with the largest fraction of retained austenite obtained from one schedule were used for studying the stability of retained austenite under cold and hot.

The aim of the paper is to compare a tensile strength and an elongation at break of the sandwich materials with different cores created with the polymeric composite mixture at simultaneous acting of the cyclic degradation. The sheet S235J0 is the face. The core of the sandwich panel is from the structural two-component adhesive, from the composite material based on the microparticles of the glass-bead, the rubber and the textile microfibre waste from the tyre recyclation and the rubber particle waste from the tyre recyclation. Namely the secondary raw materials based on the textile microfibres are difficult to utilize in another processing. This research showed one of prospective possibilities of the material utilization of this secondary raw material. The highest tensile strength of the sandwich materials is reached with the core from the composite material on the glass-bead base. The significant fall of the tensile strength of the sandwich materials was measured at the material with the core based on the rubber and textile microfibre waste from the tyre recyclation. The elongation at break was not almost changed. The core crackled at lower loading at first. The face tolerated higher loading.

The paper deals with design proposal of a cover part of a strength bumper, which is tasked with creating the outer design lines of an automobile without sharp edges according to legislation in force and also with protecting a vehicle against damage. The cover part serves for covering the strength part of a back strength bumper, which will be equipped with a winch and used in off-road vehicle Nissan Patrol Y61. Another aim is to perform a FEM analysis of the strength part of the bumper loaded by towing force of the winch and thus to verify a safety of the structure. The next solution of the issue will be an approach to real testing, which will verify a correctness of a numerical computations and also fulfilment of the purpose of creating the structure. Bases of FEM analysis and practical experimental verifications of the structure will be also used as a background for granting approvals, certifications and type approval by superior authorities.

Recent development of the application of new kinds of material in transport and production technology places higher requirements on the technologist at the determination of cutting conditions. The assortment of recent kinds of cutting material enables to intensify cutting conditions while maintaining acceptable tool durability. The dependence of tool durability on cutting speed, or "basic law of machining", is the basic means to determine tool durability at selected cutting conditions. The paper contains a suggestion to modify the original Taylor equation on recent conditions of productive machining.

This article deals with comparison of corrosion resistance of 42CrMo4 steel used for breech mechanism in the armament production. Increasing of demands on materials used for armament production and in other industrial application leads to the innovation of technologies in the field of surface treatment especially wear resistance, surface hardness, running-in properties and corrosion resistance. For the evaluation of experimental NSS corrosion resistance tests samples of 42CrMo4 steel were compared with plasma nitrided and nitrocarburized one. Individual 42CrMo4 steel samples were subsequently metallographically evaluated and characterized by hardness and microhardness measuring. The results and comparison of corrosion resistance of not-surface treated steel samples with plasma nitrided and nitrocarburized showed significant differences of corrosion rate. Due to different plasma nitriding conditions, there are corrosion resistance differences evident between the plasma nitrided steel samples as well. The corrosion resistance evaluation is supplemented by the surface corrosion-free surfaces evaluation using the laser confocal microscopy.

Article deals with problematice of influencing mechanical properties - tensile strength and hardness - of grey cast iron by heat treatment - refinement. Refinement could be in special cases applied also for grey cast iron castings in order to achieve special parameters of hardness and tensile strength of parts for specific purposes. Hardening and tempering of casting sis commonly used for ductile cast iron, but in special cases could be applied also for grey cast iron castings. Refinement - hardening and tempering - was provided on samples from materiál EN GJL 150, EN GJL 200 and EN GJL 250. Afterwards, measured values of tensile strength, hardness and fractography of materiál in poured state and after tempering on temperatures 250, 350 and 450°C after quenching from austenitization temperature 920°C were compared. Achieved results are formulated in the evaluation part of article.

The stability of the machining process is depending on the machined materials properties. But the material properties are influence by the heat treatment process and in this case it is forging. For these study three different company made the "same" forging process and then the material properties are evaluated and their influences on the cutting process were monitored. For the tests the steel DIN 18 CrNiMo 6-7 was used. This material is typically used for the gear wheels where the cutting tools by tool steel is used for the machining. So for the tests the mills from tool steel were used and during the machining the cutting tool life and cutting forces were monitored.

Deflection of cutting tools under the action of cutting forces has a significant influence on the error of machined surface and the stability of cutting process. Considering the complex geometric structure of cutting tools lead to higher calculation accuracy of the tool deflection analysis. Therefore, CAD models of double-sided solid ball end mill and helical drill bit was created in this study. The impact of tool material and clamping of the tool under the influence of cutting forces individually in three axes was obtained via finite element analysis. An error of the numerical model was less than 7.2% and has been validated by analytical calculation. Geometric errors in the case of die and mold manufacturing are provided below or close to 0.02 mm. However, due to the force effect of the cutting process it is not recommended to use HSS tools as the analysis confirmed. Stiffness of sintered carbide tools was more than doubled.

The paper deals with a machining of the aluminium alloy by means of an unconventional technology, i.e. an abrasive water jet (AWJ). The paper deals with a study of an influence of the abrasive water jet at its impact on a surface of the machined material, i.e. the aluminium alloy AlCu4Mg of a thickness 20 mm. A topography of the machined surface is evaluated within the research by means of roughness parameters. A surface analysis is also evaluated by means of a scanning electron microscopy (SEM) depending on a cutting speed and a mass flow of the abrasivum. The research results proved an increased influence of the cutting speed and the mass flow of the abrasivum. The optimum cutting speed was 50 mm.min-1, the cut was uniform without a significant grooved zone typical for cuts by means of AWJ technology.

The presented article includes a summary of the experimental works regarding the possibility of using and replacing more expensive primary alloys with secondary alloys. Although the use of secondary alloys is relatively widespread today, they are mostly used for the production of lower or medium quality castings, respectively with a low ratio of primary and secondary alloys. Experimental works was aimed at the additional processing of the secondary alloys by suitable methods or their combination, to achieve a secondary alloy with mechanical properties similar to the primary one, thus enabling the use of such an alloy to produce high-quality castings. Correctors used during experimental works are Cr, Ni, V and their combination applied to various aluminium alloys with different chemical composition.

High temperature homogenization annealing of DC cast billets from aluminium alloys used for extrusion pressing is considered as one of substantial technological operations during extrusion processing. The structure of DC cast billets consists of dendrite cell structure and contains coarse and inhomogeneously distributed intermetallic phases of β-AlFeSi and α-Al(Fe,Mn)Si type.Structure after a homogenization annealing is quite decisive for both the final properties of extrusions and the extrudability of the cast structure. The present paper deals with the medium strength heat-treatable EN AW-6082 alloy. It is investigated the effect of heating rate, time at the annealing temperature and the cooling rate of continually cast billets during the homogenization annealing on the changes of electrical conductivity, structure and intermetallic phases.

The article deals with a comparison of machining of two chemically very similar materials of aluminium alloy, however, with various internal structures by means of non-conventional machining technology of electro-erosive wire cutting (WEDM). The first material used was a right parallelepiped of ALPORAS aluminium foam with porous structure produced by a method of powder metallurgy. As the second material designed to the comparison EN AW 5005 alloy was chosen owing to high aluminium content and therefore a very near chemical composition of the compared material. The samples with circular section of identical height and nominal diameter were produced. On the tested materials sizes of the cutting width were tested, surface structures after machining were observed, dimensional accuracy of cut samples were evaluated and time relationship between cutting of compact and porous structures of aluminium alloy were defined by means of a microscope.

The purpose of this paper is to provide an overview of process and equipment improvements for nickel brush plating applications. At the beginning of this project the company used methodology from a subsidiary which does nickel brush plating. Over time, it turned out that it would require a total redesign of the process, because it wasn't compliant with Czech legislation. We knew that without improvements the process could not move forward, therefore, we mainly focused on safety, equipment, accuracy and better quality. In this work we have been using many elements from quality management such as 6Sigma methodology, Ishikawa diagrams, 5why methods, 5S, etc.
This project included many people from different sectors such as designers, technicans, material engineers, facility and maintenance, production, quality engineers, EHS engineers etc. This team came with a completely new and unique technical solution for the covered equipment which had never been built in the past in this company or by brush plating process.

Aiming at the evolution balance problem of hybrid assembly line (HAL), a dynamic (evolution) balancing model of assembly line is established, and a cooperative optimization algorithm (PSO-GA) is proposed in this paper. Firstly, HAL evolution in the market diversification and technology progress environment is studied, and assembly line evolution balance is mainly considered. In the PSO-GA, minimizing the number of stations, minimizing the load indexes of between stations and within each station, and adjusting costs are used as optimization objectives. For increasing population diversity and speeding up the searching speed, the individual information exchange and mutation are carried out in the populations. Finally, the effectiveness and feasibility of the method were proved by optimizing the HAL for an enterprise.

The use of cutting fluid increases the tool life and reduces the roughness of the machined surface. However, during the machining the oil from the hydraulic system of the machine often gets into the cutting fluid, which can alter the properties of the cutting fluid. In scientific literature there is no information on the effect of the hydraulic oil entering the cutting fluid on the tool life and roughness. In this regard, at the laboratory of the Department of Machining and Assembly of the Technical University of Liberec, there has been conducted a study to ascertain the effects of hydraulic oil getting into different types of cutting fluids during the milling of stainless steel.

Composite materials play an important role in the machine design. Laminated composites have a lot of advantages but in some cases they show different limitations that are caused by stress concentrations between layers. Discontinuous change of material properties is the reason for occurrence of interlaminar stresses that often cause delamination failure. Delaminations in layered plates and beams have been analysed by using both cohesive damage models and fracture mechanics. Modelling of composite structures by finite element (FE) codes to effectively model delamination is limited. Previous efforts to model delamination and debonding failure modes using FE codes have typically relied on ad hoc failure criteria and quasi-static fracture data. Improvements to these modelling procedures can be made by using an approach based on fracture mechanics. This approach allows us to predict the growth of a pre-existing crack or defect. A study of modelling delamination using the FE code ANSYS was conducted.

An article provides an overview of production and corresponding issues of one of the most important component of a satellite dish - a high frequency optic mirror that polarizes signals caught by a parabola into a sensor connected to computing (so-called receiver).
The article describes an issue of production of high frequency elliptic and hyperbolic optic mirrors forming one of the most important functional components of parabolic satellites designed for ALMA, the biggest and the highest located international astronomic radio telescope in the world. It is situated at a high plateau Chajnantor in Chile, South America.
Individual parts of the article are outlined in a sense of a flow of a production technological process including both theoretical and practical analyses of the given issue. A content of the article leads especially to a description and explanation of causes of individual problems during production of elliptic and hyperbolic optic mirrors.

This paper is focused on hazards in milling processes. It continues in occupational health and safety in turning. Safety rules are based on general rules and specific ones which relate to milling. It is necessary to formulate hazard and safety rules more precisely for specific production processes and in some cases for different production machines. For satisfactory solution of this problem the rules are formulated on the base of laws, regulations and personal findings of the paper's authors in enterprises. In the paper occupational health and safety hazard rules in milling on these principles are formulated.

The design of internal combustion engine use plain bearings, pistons and piston-rod which are based on aluminium, brass. Further are used steels with coating based on aluminium and bronze. The paper describes the impact of contaminants in motor oil on wear of materials, which are used in production of parts of internal combustion engine. 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 equipment simulating real frictional contact. Wear particles come into oil in lubrication system, where they cause contamination and degradation of lubricating properties and consequently it may result in major failure of machines. Among these contaminants are included mainly water, fuel, water coolant, adhesive, abrasive and fatigue particles wear. The aim of research was focused only on oil contaminated with fuel including petrol, diesel and biobutanol.

Equal-channel angular pressing is a method of severe plastic deformation, which implies high deformation into the material and leads to grain size reduction and strength increase. It was applied on a twin-roll cast Al-Mg-Sc alloy, which contained Al3(Sc,Zr) particles formed during annealing at 300 °C for 8 hours. The evolution of the microstructure and mechanical properties after deformation was studied during isochronal heating 50 K/50 min. Strengthening occurred during annealing at lower temperatures and was followed by prominent microhardness drop, which was connected with formation of new grains and recrystallization. The presence of Al3(Sc,Zr) particles in the matrix is accounted for the high temperature stability.

This article deals with unconventional materials usage in design of vehicle bodies. Main focus is on sandwich materials (with honeycomb structure) for walls of the main body. These panels are designed from polypropylene. Joining of theses sandwich panels is also solved here by special aluminium profile. Virtual simulations and stress evaluation are used methods for design evaluating. Research is focused also on material properties testing. Tested are sandwich materials and also connecting aluminium profiles. All material properties and testing principles are here clearly described. Lower weight of vehicle body leads to possibility of floor optimization. Welded frame of floor can be lighter and strength of floor is also evaluated here. All these steps lead to lighter design with economic benefits for producer.