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This essay aims to identify the composite motion and the cutting force between the grinding wheel and roller of the roll grinder. Based on the analysis of roll grinding mechanism, this essay further uses Newton's law which describes linear motion and Euler equation which describes rotation to build rolling components' Newton-Euler dynamics equation. Then the essay simplifies rolling components' virtual prototype, and uses the dynamic analysis function of ADAMS to do dynamics simulation analysis of rolling components. Finally, based on the formula to calculate grinding force, this essay testifies that calculated results are consistent with simulation results, thus providing reference data for optimization.

Internal friction reflects the ability of the material irreversibly dissipating mechanical energy oscillations. That means, the material of high internal friction ability is able to significantly reduce the vibration amplitude. Dispersion of mechanical energy in the material is just the one of the ways of energy transformation for example conversion of mechanical energy to heat energy. This article is focused on the analysis of the internal friction changes depending on the temperature. For experimental measurements was used AZ91 magnesium alloy. Measurements were performed at different excitation voltages. In experimental measurements was used only ultrasonic resonance method. This method is based on continuous excitation of oscillations of the test bar, and the entire apparatus vibrates at a frequency which is close to the resonance.

The paper deals with the production of dimensionally accurate castings of aluminum alloys in moulds of gypsum moulding mixture. This manufacturing process is very important for the production of castings for radio technology. Castings have high dimensional accuracy and high - quality of surface. Production of aluminum alloy castings in moulds of gypsum mixtures belong to a group of non-traditional methods of casting and foundry practice, this method is used for the production of special castings. Moulds and cores from gypsum mixture have specific application not only in the production of aluminum alloy castings but cast alloys with low melting temperature (tin, zinc, lead). In these days this method produces dimensionally accurate parts with high surface smoothness such as those used for radio-communication systems or propeller small blowers. Under the conditions of the Czech foundry at our institution, the Department of Engineering Technology - TU of Liberec, we devote this method for many years. The main attention is paid to the methodology for the production of gypsum moulds and their heat treatment and the correct choice of the chemical composition of the aluminum alloy in order to obtain high-quality castings.

Properties of polymeric materials are often optimized by various types of fillers. Optical analyses be means of a microscope can reveal undesirable phenomena which come into being during a preparation of composite systems - they can define areas of filler clusters, an excessive occurrence of air bubbles, which lead to an initiation of cracks. The optical analysis can reveal a low interaction among mutual phases of the composite at the same time, e.g. a low wettability of fillers by a matrix. The paper describes possibilities of using optical analysis at polymeric microparticles composites with the filler on a basis of waste with the matrix from the epoxy resin. The optical analyses identified the air bubbles in failure areas of the composite systems - the average area of the pore in 2D plane corresponded 5 381 μm2.

Surface integrity reflects the properties of a material after it has been subject to some type of manufacturing process or modification during machining process and surface integrity can also have a great impact on a parts function. The changes limit the component quality or in the same cases performed the surface as an unacceptable. It has long been known that the method of surface finishing and combination of surface roughness, residual stress, cold work, or phase transformations strongly influence the service performance of manufactured parts as fatigue or corrosion. The main aim of the article is testing a high-productive reaming tool type MT3 with respect to different values of tool-life because holes making among the most important operation in machining and one of the most common in drilling operation.

The work deals with non-destructive ultrasonic testing of butt and circumferential fillet welds in the repairing of gas pipelines. The new ultrasonic technique Phased Array was used for testing. The article compared the results of Phased Array ultrasonic inspection to X-ray inspection. Experimental samples were taken from real gas pipelines' repairs. It is a circumferential butt joint connecting 2 gas pipelines and 2 other types of circumferential fillet welds occurring during repairs of gas pipelines with pressure steel and steel patch. Experimental testing was conducted on ultrasonic flaw detector OmniScan MX2 by Olympus. Indications of defects in the weld joints obtained by ultrasonic testing are corresponding with the experimental results of X-ray inspection. Experimental results provided information for proposal of manufacture of artificial defects in these samples.

Tribology is an important method for evaluating the coefficient of friction and wear of friction pairs of technical materials. The most commonly used modes are "pin on disc", resp. "ball on disc". Tribology can simulate the stress of two objects (the friction between the objects) under the real conditions. The output of the tribological test is a specific value of the coefficient of friction and wear rate. For a comprehensive evaluation of tribological properties is used the optical microscopy - to evaluate the size of wear of the pad (groove width) and of the pin (loss of material of the ball or roller). The use of modern sophisticated equipment allows to evaluate the coefficient of friction and wear also in various environments, such as in the process fluids.

Titanium alloys are widely used in aerospace and automotive industries. They are used to implement some parts of machines, also in the chemical industry, power industry, arms industry, shipbuilding, in implantology and biomedical engineering. Extent of use of this material is mainly due to high corrosion resistance, especially in aggressive environments. These are materials with a low ratio of the weight in relation to the mechanical properties. That is, while maintaining the desired mechanical properties of structures made of titanium is lighter than the standard stainless steel.Unfortunately, the properties of titanium, in particular at temperatures higher than the affinity of the nitrogen and oxygen in the air, has an effect on some types of processing. In particular, the heat treatment as cutting or welding, due to the fact that the reaction of titanium and oxygen is highly exothermic. Therefore, the parts of the titanium produced in an inert atmosphere.

Permanent evolution of new high-strength and difficult-to-machine materials as well as production of precise and shaped products have made the engineering practice to advance towards development of technologies to allow such materials to be machined without major difficulties. In such cases, advanced machining technologies are gaining ground whose principle is based on application of physical, or combined physical and mechanical methods of forceless material removal rather than mechanical work such as conventional cutting operations. In most cases, such methods involve conversion of the energy supplied to heat which, more or less, affects the base material being machined. The most frequent technologies of this kind include machining by cutting using a plasma beam or a laser beam. The plasma beam machining and laser beam machining are both based on melting the material at extremely high temperatures. Such extremely high temperatures cause formation on an area in the base material where the structure of the material is changed by the heat down to various depths. The objective of the experiments described in this paper is to determine the size of the heat-affected zone and to identify the changes in the structure of selected types of material and their effects on further machining.

Application of cutting fluids is one of the most widely accepted methods of increasing not only the efficiency of machining but also the quality management of the working surface that is used in industry. The cutting fluid market is large enough, and different manufacturers produce their own cutting fluids in several product lines which differ as to their chemical composition and their properties. When creating a cutting fluid, the manufacturer is particularly interested in the study of its individual properties as well as studying the effect of various chemical components on the final properties of the cutting fluid. Different methods are used to study various properties of cutting fluids. This article presents the method for the study of the tribological properties of cutting fluids. This method has been applied while comparing 5 different cutting fluids.

The article describes the fundamental physical principles of the ultrasonic defectoscopy Phased Array, which provides new possibilities in the non-destructive testing (NDT) of materials, especially of welded joints. There is a report from the ultrasonic testing of welded joint with ultrasonic flaw detector OmniScan MX2 from the company Olympus NDT. The artificial defects were designed in software ESBeamTool 5 from the company Eclipse Scientific, which simulates the geometrical ultrasonic beams spread. Then, ultrasonic testing was performed at the same welded joint with artificially made defects. At the end, data from both ultrasonic testing were evaluated. The same procedure will be used for the design of ultrasonic inspection TOFD (Time of Flight Diffraction) and Phased Array at welded joints of gas pipelines.

The efficiency of the machining processes, the accuracy of the manufactured parts, and the quality of the machined surface are determined by several factors: the tool geometry, the parameters that affect the kinematic relations, and the cutting parameters. Therefore it is necessary to investigate the effect of each characteristic parameter on the technological parameters in the research of rotational turning. In this paper first we sum up the geometric and kinematic relations that affect the defining parameters of chip removal. We give an overview of the parameters which must be given in rotational turning. We briefly show the method used for the mathematic-analytic definition of these parameters. After that we determinate and analyse the alteration effect of the inclination angle on the resultant axial feed, on the theoretical arithmetic mean deviation and on the characteristic parameters of the chip cross-section.

The article describes mathematical model and possible usage of results of dynamic loading simulation of the chassis of track vehicle. The computational model is designed for computational simulating system MSC.ADAMS.AVT. Possibilities of research results usage are described in the article mainly. Results of simulation calculations were used for make-up of constructional parameters parts file of vehicle chassis and findings of influence their changes on changes of directional vehicle stability by running at first. Make - up of approximate relations for transaction of fast orientation calculations is second described possibility of results simulation calculations usage. The possibility of usage of results simulation to do verification of mathematical model is third possibility of usage results simulation calculations. The optimization of influence changes of several design value together is fourth possibility of usage of results simulation calculations that is described in this article.

Secondary and backscaterred electrons are the most common signals used for imaging in the scanning electron microscopy. Generally, SE are used to obtain topographical contrast while BSE show differences in chemical composition (so called Z-contrast).The aim of the present work is to show possibilities and techniques to obtain not-so-common information using BSE, as e.g. orientation contrast, residual stress, different allotropic modifications, etc.

Zn-Mg alloys, in which Mg is an alloying element, are proposed for medical applications as a promising biodegradable material for temporary implants in orthopedics or traumatology. They can be used to replace nonfunctional or damaged tissues. When the healing process of tissues is finished, the Zn-Mg alloys are gradually decomposed in a human body and a reoperation is therefore unnecessary. Their mechanical properties must be similar to the characteristics of human bones. Large grains are typical for the structure of cast alloys. Pure Zn and Zn-0.8Mg alloy were cast and subsequently extruded at 300°C. The structure and mechanical properties (Vickers hardness, compressive and tensile strength tests) of the cast alloys were compared with those of the extruded alloys. Pure Zn and Zn-0.8Mg alloy after the extrusion had a fine-grained structure and showed better values of mechanical properties in comparison with the cast alloys.

Introduction into problems - It is expected that the measured value of the hardness will not be dependent on the applied test load and operators carried out the measurement. The Vickers hardness tester was calibrated by three operators using loads between 49.03 and 980.7 N and one CRM (standard) for a full load range. The uncertainty of obtained results was calculated in accord with standard ISO 6507-2 and tolerances analyze method. The capability of the calibration was evaluated by GRR method of the Measurement systems analysis (MSA). The method of total dispersion zone was used for estimation the impact of the variability between operators at particular loads on the measured value of the hardness. The influence of the load on the hardness expressed by Meyer's index "n" excluded ISE (indentation size effect). The influence of operators on the resultant hardness is weak, and the impact of applied load is ambiguous. The values of uncertainty calculated in accordance with the standard and by tolerance analysis are comparable.

Adhesive bonds are very often applied in various climatic conditions and environments. Each environment is of specific properties which basically influence entire strength and reliability of an adhesive bond. The influence of the surroundings temperature on the strength and service life of the adhesive bond is one of the most important factors which has to be taken into regard by a designer when designing the bond. However, during a transit or a storing the adhesives can meet much higher or lower temperatures than it is recommended by a producer. The aim of the experimental part is a determination of the influence of the storing temperature in the interval -20 to 100 °C on the resultant strength of the adhesive bond. Two-component epoxy and acrylate adhesives which are used as the constructional ones were used for experiments. The subject of the research was the adhesives which are not specially determined for using in high or low temperatures. From the results it is obvious that the packing type is essential for a transfer of surroundings temperature into the adhesive. Higher storing temperatures (temperatures exceeding 60 °C) affect in a negative way the adhesive bond strength.

The paper deals with an analysis of preheating and heat treatment after welding and their influence on the final hardness level in case of welded jonits for common materials applied for manufacture of pressure vessel plates. During the welding process, the higher values of hardness and simultaneously decreasing of plasticity was observed and measured in the heat affected zone. Therefore, there was necessary to preheat the base material, or to apply the heat treatment after welding, or to suggest any combination of both mentioned ways. First of all, the groups of tested plates with required parameters were chosen for the application of the submerged arc welding method (according to ČSN EN ISO 4063), and preparation of samples for hardness measurement (ČSN EN ISO 6507) as the next step. The main goal of this experiment was to determine the hardness level for two fine grained steel grades after welding with the given parameters, as well as to adjust or to eliminiate the heat treatment process (preheating, post-heating), if they are not necessary.

Presented research paper is focused on the development of train front end cab, specifically on choice of material composition and production technology. Experimental part deals with a selection of the most appropriate multiaxial fabric based on its saturation by resin and type of polyester resin most suitable for low-pressure vacuum infusion. This technology is chosen with respect to dimensions of the part, resin savings (compared to hand lay-up technology) and also production cost of the cab. Prepared samples are evaluated regarding to the progress of production technology, part face quality (voids, dry spots, and delamination) and technological properties. As a result, optimal material composition for front end cab production is chosen and fabrication of prototype cab is conducted.

Using cutting fluids often enables an increase of cutting tool life. A large amount of cutting fluids produced in the European Union exists on the market of Czech Republic. It is quite difficult for purchasers of cutting fluids to acquire reliable test data about the performance of the fluids in industrial conditions and choose the best cutting fluid, the use of which will guarantee the longest tool life. In this regard comparative tests of cutting fluids were conducted at the laboratory of the Department of Machining and Assembly of the Technical University of Liberec to determine the effect of cutting fluids from different producers (from England, Germany, Norway and Switzerland) on tool life in turning and milling.

This paper describes the dependence of microstructure of NiTi shape memory alloy on the conditions of nonconventional powder metallurgy processing routes - reactive sintering of compressed Ni+Ti powder mixture and mechanical alloying with consequent compaction by Spark Plasma Sintering. First method was chosen as the process enabling to yield the high-purity NiTi alloy, while the second one aimed to reach the ultrafine-grained microstructure. The microstructure and phase composition of the products are compared in this work. The positive effects of high heating rate (> 300 K.min-1) and high temperature (at least 900 °C) on the reactive sintering process were recognized. Microstructure of the product is composed by NiTi matrix with dispersed Ti2Ni particles. Similar microstructure can be also obtained by mechanical alloying for at least 120 min and consequent compaction by Spark Plasma Sintering.

The paper deals with some problems of quantitative metallography which includes evaluation of microstructure by etalons, measurement of structural parameters by coherent test grids and automatical image analysis. Some advantages and disadvantages of these methods are shown in this contribution on the example of evaluation of microstructure of graphitic cast irons. The automatical image analysis enables to eliminate some disadvantages of evaluation of microstructure by etalons and by coherent test grids but it has also some negatives.

The paper deals with capacitor discharge welding of aluminum studs type AlMg3 on two different materials (aluminum sheet of the same chemical composition with a thickness of 1.5 mm, and the magnesium sheet, material AZ61 and thickness 1 mm). Influences of welding parameters on the mechanical properties of the weld joints and the creation of typical defects were examined. For assessing the quality of weld joints, a series of tests were made: micro hardness test, bend test, torque test, test of macro and microstructure and SEM analysis on the electron microscope. The results are presented in the paper including suggestions for welded joints of required quality.

Nowadays is issue investigation the notch problems and their influence on component durability. For many manufactured components, we find various types of notches, such as grooves, step and holes. They have a tend to be the place where is concentrated stress, so called the macroscopic stress concentrator. In this area is higher risk of part destruction. Nowadays, there are hypotheses that are based on the assumption that the higher the roughness, the lower the durability. In many cases the designers prescribe unnecessarily high surface quality. It is necessary to maintain adequate quality of the surface, and also necessary that the component has attained a high durability. The paper deals with the influence of machining technology carrying capacity of notched components. As the test material was used steel Fe510 according to EN ISO (11523, according to CSN 42 0002).

A production stroke has to be taken into regard also at using bonding methods. A limit in an area of the adhesive bonding technology is long hardening time which is needed for reaching a handling strength. Second solution is using quick hardened adhesives (cyanoacrylates). Second limit is a necessity to treat the adhesive bonded surface which is regarded in production companies as another cost and a problem in an area of a waste economy. The paper deals with the necessity to mechanically treat the adhesive bonded surface, that means an influence of links in the boundary of the adhesive bonded material and the adhesive. The aim of the research is to set the influence of the mechanical and chemical surface treatment of the steel surface at an application of cyanoacrylate adhesives on a strength of the adhesive bond.

Molds used for pressing refractory fireclay shapes are exposed to very strong abrasive wear, which is given by the combination of applied pressure of more than 60MPa and processed materials like alumina (Al2O3) and silica (SiO2). Typical lifespan of molds is in several thousand cycles, our aim was to improve the lifespan 10 fold at minimum. To increase the lifespan of the critical parts of the molds, it was decided to use HVOF coating technology based on WC. This article evaluates the quality of the coating on the pins for pressing tools based on the technology used for deposition. An analysis was made on two sets of HVOF coated pins from different suppliers marked as a sample "A and B". Pins were analysed on tactile CMM with scanning system and samples from these pins were analysed on a multisensor CMM.

The compaction of powder metals and alloys is very difficult field due to preserving of unique properties of initial materials. One of few possible method of succesful compaction is plasma sintering. To describe detailed structure os powder metallurgy materials, it is necesary to use advanced microscopy methods such as SEM and TEM. In this study, the structure of NiAl intermetallic compaoud is described. The material was at first produce by reactive sintering from pure elements. Subsequently, the NiAl porous master alloy was milled and compacted by spark plasma sintering (SPS) technique.The particle size of NiAl powder was compareable to the grain size of compact material, which exhibited low porosity. It was proven that the interconnection on NiAl particles is performed by thin layer of nanocrystalline oxides.

The iron aluminides seem to be a promising materials for high-temperature applications. They have a wide range of positive properties, but unfortunately also some negative (for example low ductility at room temperature or sharp drop in strength above 600°C). The addition of third element into the alloy can be the way to improvement of the properties. Nb, Zr or Ta seem to be appropriate elements. The niobium addition to the Fe-Al matrix leads to the formation of Laves phase. If the Laves phase is presented in an appropriate shape, it could enhance high temperature mechanical properties. These properties are dependent on the structure of alloy - mainly on second phase distribution and type.Two alloys with different content of niobium were investigated. The influence of niobium content and heat treatment on the structure and mechanical properties of the alloys were studied. The phase composition was determined using scanning electron microscopy (SEM) equipped by energy dispersive analysis (EDX) and electron backscattered diffraction detector (EBSD). This paper is the first part of study and it deals with description of the alloy structure and phases in the investigated materials.

This paper deals with influence of tool wear on surface integrity after hard turning expressed mainly through the Barkhausen noise responses. Grinding operations can be sometimes replaced by hard machining (hard turning and milling). Chip separation in hard turning differs from mechanism of chip separation during grinding. For this reason surface integrity expressed in variable terms differs. Surface integrity can be expressed in such term as surface roughness, shape deviations as well as characteristics such as residual stresses, structure transformations, and microhardness alteration. Being so, it can be beneficial to apply the suitable nondestructive surface testing techniques to obtain information about surface integrity expressed in complexity of this term. Nowadays, Barkhausen noise technique is widely used in a variety of industrial applications. This technique is sensitive to stress state as well as microstructure features. For this reason, Barkhausen noise emission is used in this study to reveal magnetic and stress anisotropy developed in a certain stage of tool wear. The paper also discusses very high BN responses associated with the specific aspects of produced surfaces.