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In the production of polymer parts, great emphasis is placed on the quality of polymer product in terms of dimensional accuracy and optimally surface quality. Achievement of high surface quality of injection molded products correlate to the high surface quality of core or cavity in injection molds. This surface is copied during injection of polymer material. The kind of polymer material and its rheological properties can strongly influence this surface copying. Production of cores and cavities takes in the manufacturing process a considerable part of time, where some finishing technologies are more economically and time consuming than other processes. Thus, it is necessary to choose an appropriate finishing operations considering cost of injection mold, which is reflected in future price of polymer product. This paper experimentally examines the influence of the surface quality of mold cavities and rheological properties of polymer on the surface quality of injection molded product.

Presented article deals with designing of the novel technology for repairing of the defects in branch connections of the gas pipelines. Until now, defects of the branch connections could be repaired mainly by replacing of the damaged area, especially those allied with gas leakage. The most important requirement of new type of repairing technology is maximal allowable operational pressure, which has to be the same as for repaired pipeline. Dimensions of the split sleeve should be thus designed according to required pressure value. In the case of split sleeve for branch connections, dimensions were determined by the static analysis in ANSYS software. Designed sleeve was after manufacturing process subjected to pressure testing by standardised test to confirm requirements of the standards. Pressure test to destruction was performed in order to determine the weakest place of construction. Proposed repairing solution might lead to reducing of the costs for performing of the branch connections repairs.

Absolute length calibration of gauge blocks traceable to the definition of meter is an important task of the national metrology institutes responsible for providing reliable length artifacts for industrial use. The length of a gauge block (henceforth, represented as GB) is defined in ISO 3650 as the distance between its one measuring face and the surface of an auxiliary platen on which the other measuring face has been wrung. Accordingly, in central length calibration of K-grade GBs using interferometry, it is required that they be wrung onto an auxiliary platen whose characteristics are the same as the measuring face of the GBs. According to this definition, the length of a GB consists of its mechanical length between two faces and the wringing film thickness. This definition is practical and reasonable in many cases because GBs are used as length standards with wringing. Also this calibration method has the advantage that the thickness of the wringing film is propagated appropriately when lower grade GBs are calibrated by comparison to higher grade GBs via a mechanical comparator. In terms of this paper is briefly described interferometry method of gauge blocks calibration. The paper was written in conjunction with Czech Metrology Institute.

3D printing is a new and advanced technology of material processing, which belongs to additive manufacturing process. Products with complex geometries can be produced quickly with high precision from powder materials on the base of a CAD-model. Layers of powder particles are successively molten by laser beam. There are several metallographic issues connected with 3D printed microstructures. Laser beam processing is usually accompanied with high heating and cooling rates and therefore also with high thermal gradients. This is the reason why nonequilibrium phases and structural components can occur in the final microstructure. The microstructure could be also finer in comparison with the one produced by standard manufacturing methods. Porosity of the final microstructure is also an important factor, as it might deteriorate mechanical properties of the product. Thorough metallographic analysis of 3D printed materials is therefore necessary to ensure high quality of final components.

The article deals with the prediction of diffusion process of steel components, respectively diffusion of carbon during carburizing. The calculation was made on the basis of the solution diffusion in semi-infinite space. For the calculation there was used the II. Fick's law. For the reason that the transfer medium is formed at the interface environments diffusion boundary layer, for the more accurate calculations, it is necessary to consider the coefficient of transfer of β atoms of carbon. For the calculation of the diffusion coefficient D was used Arrhenius's equation, which is based on the rate of diffusion processes (diffusion). It was calculated the time for diffusion of carbon to achieve the concentration of 0.8% C. There was also made a calculation of carbon diffusion in the gear from material EN DIN 1.7142 (DIN 14221). Diffusion was performed at 950 ° C, the initial concentration of carbon was 0.2%. Carburizing carbon concentration was 1.1% C and carburizing time was 1, 3 and 6 hours.

The article deals with contactless thermal forming of metals. In the introduction the bending theory of components by using flame technology is described. On the basics of information obtained from the analysis of previous research a technological procedure was developed. This technology uses gained characteristics of material behavior in the process of heterogeneous circumferential heating. The principal of material concentrating in the process of local heating the area which is placed in a quasi prism leads to a bending moment. This bending moment evokes deformation of the material which was compacted this way. Application of subscribed technology pushes the limits of forming to a higher level because by using conventional forming processes the trajectory of the component is not straight but curved. Because of this phenomenon it would be necessary to apply forming tools which dynamically change and do not still exist.

Drill bits used for machining of composite materials can have different geometries and it is difficult to choose suitable geometry for a specific type of composite. Unsuitable geometry of a drill bit leads to bad surface quality. The objective of this paper is to find the most suitable drill bit geometry for machining of the thermoplastic composite C/PPS in terms of surface quality and magnitude of thrust force under different cutting conditions. Three drill bits were chosen for experimental investigation. A significant influence of the point angle was identified. A gradually decreased point angle together with an increased rake angle of the cutting edge lead to better surface quality. In addition, investigation of the influence of cutting conditions on surface quality and cutting forces was performed. A considerable influence of feed was observed in comparison to cutting velocity. Information included in this paper can help to design more suitable technology for drilling of thermoplastic composites.

Semi-solid processing allows novel microstructures to be produced even in conventional materials. This is thanks to the peculiar conditions of the process and the rapid solidification. Despite that, semi-solid processing is not widely used in practice due to its technological complexity. Mini-thixoforming is an innovative method of processing metals in the region between their solidus and liquidus temperatures. With its small volume of the metal feedstock, it is a very precise and highly dynamic process. Consequently, it can be employed for materials with a very narrow freezing range which, until now, were impossible to thixoform conventionally. The present experiment focused on one of such materials: the low-carbon high-alloy age-hardenable X5CrNiCuNb16-4 steel. Owing to the low carbon level, the relevant temperature interval was 1380 - 1420 °C which, together with the need for strict control, posed a technological challenge. Once the semi-solid processing parameters were optimized, the die cavity was filled as required and the final products showed good surface quality. The resulting single-phase microstructure consisted of ferrite. Hence, given the 17% level of dissolved chromium, there is a potential for excellent corrosion resistance and, possibly, for subsequent age hardening of the material

The article deals with the influence of the holders speed on the final radius size of the cutting edge. The reason why is investigated radius of cutting edge is that its size affects important parameters in machining process. For example, these parameters are geometrical accuracy of machined components, cutting tool life and stability of machining. Futhermore, it is forces on the cutting edge and thermal influence on the tool. In the experiment five variants are used, prepared by drag finishing. The main variable parameter is holder speed. The aim is to confirm or refute the imput idea. This idea is based on the theory, that the higher holders speed will increase the intensity of drag finishing process. The results are measured and analysed on microscope IFM G4.

The paper deals with simulation analysis of a rail vehicle with a tilting bogie. The goal is to determine the wheel force in the rail-wheel contact and subsequently determine the safety against derailment. The rail vehicle model was designed in CAD program CATIA and imported to program SIMPACK with the RAIL module extension afterwards. Eight variants of different velocity, vehicle occupancy and setting of the tilting mechanism were analysed. The vehicle model was run along a track composed of straight sections and four succesive curves. Diagrams of the examined quantities icluding the lateral flanging force, vertical wheel load and the safety against derailment for the eight different variants make the result of the simulation analysis. Arising from the analysis, the biggest differences of results can be seen between the two variants of the highest speed but with different occupancy.

The article deals with the causes of degradation of weld joints, reducing the structural stability of joints in determining of the carbon coefficient, depending on the bandwidth, due to thermally activated happening.

To improve mechanical properties of adhesive bonds and to reduce an amount of an adhesive spherical particles or fibres are used. Glass and carbon fibres are mostly used types of fibres, however, they are not environmental friendly. So biodegradable materials, namely jute, cotton and linen were used for experiments. The aim of the experiment is to clarify the fatigue behaviour of structural two-component epoxy adhesive applied to a constructional steel S235J0. The fabrics were composed of jute, cotton and linen in a plain weave and the weights in grams 140g/m2 for cotton, 261g/m2 for linen and 305g/m2 for jute were used. The specimens for quasi-static and lap shear strength tests were made in accordance with EN 1465:2009. It is obvious from the experiment results that it came to the improvement of the quasi-static loading at adhesive bonds reinforced with linen, the increase of static strength was about 28 % compared with bonds without fabric layer.

This work is focused on the description of the influence of the particle size of nickel on the synthesis of NiTi shape memory alloy by reactive sintering with high heating rate (300 °C.min-1). It was found that coarse nickel powders undergo only a limited thermally-activated reaction. On the other hand, too fine powders support the low-temperature (500-800 °C) diffusional formation of Ni-Ti intermetallics which could then suppress the rapid thermally-activated reaction. The optimum powder fraction of nickel to obtain the material with the lowest porosity and fraction of undesirable Ti2Ni phase is 25-45 μm.

The aim of this article is proposition of new methodology of experimental analysis of long-term monitoring of sandwich composite structures. The sandwich composite structures are, due to its properties like stiffness, high impact strength, corrosion resistance, low thermal conductivity and low acoustic conductivity and, commonly used in civil engineering in recent years. This type of structure is composed of two main parts (face sheet and core) having different material and mechanical properties. Sudden change of these properties causes interlaminar stress in structure. A good knowledge about behaviour of sandwich composite structure is important for efficient manufacture techniques, long-term prediction of structure behaviour and for economics. The experimental part has been focused on obtaining the experimental results of deformation between layers of sandwich composite structure during long-term monitoring. The long-gauge optical fibres SOFO® SMARTape Compact have been used for long-term monitoring of sandwich composite structures. Long-gauge optical fibres were placed between the foam core and an outer layer of the composite structure during manufacturing. Test specimens were loaded in three-point bending test.

The article is aimed on the analysis of the internal damping changes depending on the amplitude of the magnesium alloys AZ31 and AZ91 in as cast state. In experimental measurements was used only resonance method, which is based on continuous excitation of oscillations of the specimen and the entire apparatus vibrates at a frequency which is near to the resonance. Starting resonance frequency for all measurements was about f = 20470 Hz. These mechanisms have been studied by ultrasonic resonant apparatus. Damping capacity of alloys is closely tied to the presence of defects including solute atoms, second phases and voids. The interaction between moving dislocations and point defects is one of the major internal damping mechanisms of magnesium alloys so the precipitates influence the damping capacity and contribute to damping properties.

The article deals with the calculation of stiffness of a secondary suspension spring built in a bogie of a rail vehicle with a tilting car body. The vertical stiffness of the springs was calculated using the ANSYS program. The results were compared with calculated values afterwards. The lateral stiffness was evaluated in a similar manner. Analytical method by Gross, Wahl, Budrick, Timoshenko and Ponomarev was used for comparison with numerical values. The ANSYS simulation was performed for calculating the vertical stiffness of the triple springs. The most suitable analytical method is a method by Timoshenko and Ponomarev, where the percentage difference was the smallest. The obtained data will be used as an input for the design of coil springs which will be implemented in a model of a vehicle with a tilting car body, for which the comfort values during transition in curve will eventually be determined.

This paper deals with the possibility of spent portable batteries treatment with the aim of zinc recovery. Perspective of pyrometallurgical and hydrometallurgical process is described. Samples of zinc based portable batteries were submitted under the investigation. Aim of the work was to find the best conditions for zinc recovery. Experimental work focused on hydrometallurgical process was conducted. Results have shown 100 % zinc recovery under these conditions: leaching in medium 2 M (NH4)2CO3, addition of 20 ml of NH4OH as reductant, leaching temperature 20°C, within 10 minutes.

The subject of this study is the analysis of vibrations induced during milling of a thin-walled element. The milling was performed with a 2-flute custom end mill for machining Al alloys (FENES, 12x22x80-45°W-Z2), diameter d=12 mm. The rectangular 7075-T651 aluminium alloy workpiece of the following original dimensions: 120x60x12, was machined in a DMG MORI DMU 65 MonoBLOCK 5-axis milling machine. The vibrations of the aluminium alloy test plate were identified with Siemens LMS Scadas Mobile system and LMS Test Lab software. A PCB Piezotronics triaxial ICP accelerometer (model 356B21), offering sensitivity of 10mV/g, was employed. The sampling frequency was 11.5 kHz. The first stage consisted in measuring the vibration levels of the sample, in the function of its thickness and federate vf, at constant technological parameters of machining. The feed vf was set to 1500, 2000, 2500 and 3000mm/min, the depth of cut ap =2mm, the cutting speed was constant and equal to vc = 150.7 m/min (n=4000rev/min). The wall thickness b of samples was equal to: 30mm - reference sample and 11, 9, 7, 5, 3mm - test samples. The vibration signal was measured by two sensors attached to the surface of the sample in two extreme positions on the sample: point P1 and point P2.

This paper aims to design a control jig for cutting inserts measurement. These inserts are made from standardized inserts by grinding. The control jig is intended to be used on two different types of measuring devices and it has to meet the functional requirements of these devices.The intoduction describes specific functional requirements on the jig, provides information about measuring devices and examples of cutting edges grinded on inserts. Next part describes the design of several variants of jig parts and reasons for their application. Paper is focused specifically on design of jig body variants, description of measuring arm and the way of clamping of inserts in the control jig. The measuring range is described for each of proposed variant. In the closing part of the article particular variants are compared according to their suitability, stability during measuring and range of serviceability for measuring of the inserts.

This paper was based on the cooperation the Department of Machining, Assembly and Engineering Metrology with company accredited by Czech Institute for Accreditation. It deals with issues of calibration 3D indicators. Generally, the calibration of non-specified working gauges integral part of every company, which uses such gauges. Checking/calibration of measuring instruments is important for ensuring the uniformity and accuracy of measurements to ensure continuity of measurement results. The paper deals with streamlining the process of calibration of indicators 3D design and practical verification of appropriate gauge for the calibration. The target of innovation is to eliminate the errors and shortcomings of the current solutions. In the conclusion are the results of calibration by help current and new solution checking device and their comparison.

In particular, the quantitative and qualitative results of the technological process are in most cases determined by the level of finishing operations, which include in particular grinding. It is characterized by high precision, the accuracy of geometric shape and generally very good quality surface. One of the factors to achieve the desired quality of finished surfaces, in particular, knowledge of the effect of temperature of the contact surface of the grinding wheel and the ground. In the article is the methodology of the quantification of the impact of cutting parameters on the temperature of the grinding. Another requirement is the right choice of other cutting parameters, to guarantee the achievement of the required accuracy dimensions and shape, increase performance and decrease the temperature of the contact of the cut surface with a grinding wheel.
The result is the desired surface integrity and the exclusion of undesirable residual stress in the lustre of the surface. In the case of the quantification of the individual characteristics of the grinding on the optimization of the grinding process, it is possible to achieve this objective

Mechanical vibration is undesirable in the majority of cases. It can have a negative influence on accuracy of manufacture, service life of processing equipment and tools, labour protection, human health and so on. Excessive noise belongs to the accompanying phenomena of the mechanical vibration too. For these reasons it is necessary to eliminate mechanical vibration in an appropriate manner. There are different possibilities of vibration damping. Application of suitable materials with damping effects belongs to these possibilities. This paper is focused on structural damping of materials. Damping properties of different materials were experimentally measured and subsequently evaluated by means of the forced oscillation method. It was found that the vibration damping depends not only on the material type but also on material density and thickness, excitation frequency and mass load.

Selective laser melting (SLM) is one of additive manufacturing technologies capable of processing metallic materials. The quality of final product is influenced by a variety of parameters. Although this technology has been studied intensively for several years, the optimal setting is still in search as these parameters vary with different materials, different designs and alike. The layer-by-layer manufacturing approach brings about several characteristic features. Therefore, this study is focused on observation of characteristic microstructure evolution, resulting surface morphology and changes in surface chemistry when SLM is applied in processing of titanium alloy Ti-6Al-4V and AISI 316L stainless steel. As these materials represent most widely used implantable biomaterials, their surface properties are of particular importance.

Degradation of technical objects is a natural phenomenon, but for users of these objects brings many problems. These problems are manifested by shortening lifetime, lowering safety and increasing costs for the technical operation of technical objects. This article analyzes the causes of degradation of parts steam generator using methods of microscopy. Degradation processes that occur most frequently in parts of steam generators are creep, corrosion and wear. The degradation occurred on the tube of convection superheater from steel CSN 41 5128. It was found that the inner surface was covered with corrosion products and was disrupted its cohesion. For search of the causes of degradation were used spectral analysis, microscopic analysis and determination of the weight of oxide layers according to CSN ISO 8407. Based on the results of analyzes, it was found that the occurrence of degradation is related both microstructure of pipes which did not comply with the required state and also with non-standard environment, which was exposed the inner pipe surface.

The article presents the microstructure and mechanical properties of aluminium cylinder head engine. The cylinder heads are manufactured by gravity casting. Gravity casting (GC) is very good process for making complex mechanical parts of light metal like aluminium alloys. However recently another light metal has come to the forefront in the quest for fighter vehicles and improved fuel economy. The most commonly used aluminium alloy for gravity casting automotive components is the Al-Si-Mg type. AlSi10Mg is a good purity of aluminium alloy with good corrosion resistance, very good mechanical properties and good castability. AlSi10Mg alloy is slightly hypoeutectic with a low content of accompanying elements and impurities. Exhibits excellent casting and technological properties (good machinability and corrosion resistance). During solidification of this alloy is formed a shrinkage, which is necessary to eliminate by risering. This alloy has a wide foundry application, it is used for gravity casting into metal moulds for production of cylinder heads. This alloy is used for precipitation hardening intermediate Mg2Si phase. It was cast a cylinder head of AlSi10MgMn alloy and it was monitored the structure of the casting.

The article will describe investigation of the deformation of stainless steel during three-point bending cyclic loading with using thermovision. The analysis will prove different temperature response to external loading and dependence of elastic or plastic deformation development on material's state. The input data which are necessary for this analysis we will can get from temperature field of specimen surface. Process of elastic and plastic deformation is in dependence on radiation emitted by the object. For obtain thermal fields we will use thermal camera FLIR SC7000 with the highest sensitivity. The contribution also presents results of fatigue resistance of austenitic stainless steel AISI 316L, which is used as a biomaterial, obtained at low frequency cyclic loading in the high cycle fatigue region by three-point bending test. The fracture surface of the testing sample was examined using scanning electron microscopy (SEM).

This paper presents the nonlinear analysis of the reinforced concrete buildings of nuclear power plant under the aircraft attack. The response from the nonlinear analysis was considered taken the deterministic calculation procedures. The dynamic load is defined in time on base of the airplane impact simulations considering the real stiffness, masses, direc-tion and velocity of the flight. The dynamic response is calculated in the system ANSYS using the transient nonlinear analysis solution method. The damage of the concrete wall is evaluated in accordance with the standard NDRC consid-ering the spalling, scabbing and perforation effects. The simple and detailed calculations of the wall damage are compared.

The contribution is dedicated to surface integrity assessment of components from the point of view of residual stress profile after machining and finishing technologies. Residual stresses play the key role for dynamic life and service reliability of the part, especially rotating aircraft airfoils made of titanium and nickel base alloys. Except a brief summary of measurement methods practical experience with application of Beam deflection method combined with electrolytic etching is published. Specific measurement results for real aircraft Ti6Al4V airfoils and Ti6Al4V plates following its manufacturing technology are the subject of experimental part.

Welding of the dissimilar weld joints is allied with some technological difficulties that might affect the operational time of the construction. Between the main problems belong presence of residual stresses and inappropriate microstructure of the heat affected zone on the side of ferritic steel resulting to increased hardness. These factors are significantly influenced by heat input during welding, its appropriate control and welding sequence. Optimisation of the heat input and welding sequence requires large amount of experimental work. Recently, numerical analysis of welding based on finite element models became a successfull tool for prediction of material behaviour during the process. This article deals with numerical analysis of austenitic X5CrNi18-10 and ferritic S355J2H steel welding.

This article presents particular results from a long term research focused on machining of INCONEL alloys. As a representative of this group of material INCONEL 738LC is selected and the article presents results of different experiments conducted. The behavior of material under different conditions was evaluated with focus to define cutting condition that can be recommended as suitable cutting conditions for profile milling of material. Basic problems of profile milling are exposed with focus to the respective material. Several machining experiments are explained and archived results are discussed. Effect of tool geometry and geometrical constraints and relations during profile milling is defined. Tool wear and cutting forces were measured and evaluated. The final conclusion is a recommendation for successful machining of given material.