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The paper describes specific phenomena of semi-solid casting process, especially rheo-casting method SEED, which uses mechanical swirling for reaching proper structure in semi-solid state. The eutectic segregation during processing of semi-solid slurry can cause specific casting defects. Heat treated alloy AlSi7Mg0.3 was applied for producing castings. For observing structure, metallographic observation by light and SEM microscopy was used as well as spectral analysis.

Usually, the coatings used in industrial applications require post-processing to reach their final shape. However, some of these coatings are difficult-to-cut, mainly because of their high hardness. The present study provides a revision of some experimental investigations on the turning of WC-Co, Stellite, and Fe-based and NiAl alloys. The materials are used for both coatings and sintered workpieces providing insights for conducting turning tests. For the success of the turning process, the selection of the machining parameters is a critical issue. Based on the reviewed investigations, the surface roughness is clearly influenced by the feed rate, expecting higher values than the ones predicted by the theoretical equations. Besides, the increase of both the cutting speed and feed rate leads to a high tool wear. Likewise, the increase of the feed rate leads to higher machining forces. In general, the influence of the cutting speed and depth of cut is less evident. Regarding the machining parameters, usually their maximum values are fixed at low levels: 100 m/min, 0.35 mm/rev and 0.3 mm, for the cutting speed, feed rate and depth of cut, respectively.

The aim of the research was to compare a classical (turning) machining and an abrasive-free ultrasonic machining (bufo) at aluminium alloy. An ultrasonic set I - 4 consisted of the ultrasonic generator, power output 630 W and working frequency 22 kHz ± 10%, was used for the research. Three different cutting fluids containing nanoparticles were compared at the abrasive-free ultrasonic finishing. A rise of a hardness HV0.05 and HBW2.5/62.5 compared to the classical machining occurred at the application of the abrasive-free ultrasonic machining technology at the aluminium alloy by various cutting fluids containing nanoparticles. It is obvious from the results that a considerable fall of the surface roughness parameters Ra and Rz occurred at the application using the abrasive-free ultrasonic finishing.

The structural entirety of any biomaterial has to be tested to inhibit to untimely failure and thus maintaining the reliability of the replacement. The knowledge of dielectric properties (relative permittivity, loss factor) of biomaterial without defects in defined microwave frequency range (8-12 GHz) and subsequently comparing properties in defective material as changes in material and classifying the occurrence of inhomogeneities as on the surface so inside the structure. This article deals with possibility to create dental phantom with the same properties as used in practice and dielectric properties measurement method (Hippel method). We made phantom from poly methyl methacrylate (PMMA). PMMA is very commonly used dental material as crown of human tooth or as the crown for intra-osseous dental implantant.

Cutting fluids are complex mixtures used to cool, lubricate and remove metal chips from tools and metal parts during grinding, cutting, or boring operations. Utilization of cutting fluids in the technological process of metalworking often generates aerosols which represent a significant hazard to the safety of workers and to the environment. The paper deals with the research of cutting fluid's impact on aerosol production by expressing particle size distribution. We used a special image analysis algorithm for the data obtained by a high-speed camera to determine the particle size. The procedure of result assessment was created for measuring the size of small droplets and it was implemented in a MATLAB application. Multifactor analysis of variance (ANOVA) and nonparametric analysis of variance were used for statistical result evaluation.

Ammunition projectiles disposal armored facilities used hard core as the main effect. The hard core has a smaller diameter than the calibre of gun. The core of the projectile is made of tungsten carbide, titanium, molybdenum or depleted uranium with a hardness of 80 to 120 measures by the Rockwell hardness test. The core must be not only hard but also tough and have a high bending strength. Knowledge of the hard core chemical composition, which the attacker uses, is important in relation to provide ballistic protection, minimization of radioactive risk and optimization of conditions for disposing of old ammunition. The basic tool for detection of the necessary data is material analysis. This analysis provides information about the weight, chemical composition and material microstructure of the hard core.

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 is focused on the analysis of the internal damping changes depending on the amplitude of the magnesium alloys AZ31 and AZ91 in as cast state and after homogenization annealing. In experimental measurements only resonance method was used. This method 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 = 20500 Hz.

Dynamic characteristics of a machine-tool-workpiece system are not constant during machining, but they can be changed by a variable spindle position, a rising tool wear or a gradual change of a workpiece geometry. This paper deals with an influence of spindle unit extrusion on stability of a machining process. Two milling cutters with different rigidity, flexible and stiff, were used for experimental machining at three axis milling machines. Clamped milling cutters were extracted systematically and a frequency response function was measured simultaneously. Reached data (natural frequency and dynamic compliance) were used for finding a correlation between dynamic parameters and extrusion of the spindle. Critical extrusion of the spindle unit was predicted by an experimental measurement and an axial depth of cut thresholds was established for the stable machining.

Different powder metallurgical techniques have been intensively studied as candidates of methods suitable for fabrication of metallic biomaterials intended for orthopedic applications. The main advantage of powder metallurgical products is that they contain porosity which compromises their mechanical properties closer to those of human bone and allows transport of bodily fluid and growth of ne tissue through the implant. This enhances the healing process; moreover, the pores may be also impregnated by drugs or growth factors, which are eluted during healing and support the healing process. Recently, Ti-based and Mg-based materials have been the most investigated metallic biomaterials; therefore, the powder metallurgical methods are usually studied on those materials. In this paper, the most investigated methods will be summarized and briefly described.

The article is aimed on present research of internal friction mechanisms that are responsible for the temperature behaviour of AZ91 magnesium alloys. These mechanisms have been studied by ultrasonic resonant apparatus at a frequency close to 20470 Hz and in a temperature range from 50 °C up to 400 °C. The specimen on internal friction measurement has an hour glass shape. The specimens were in the as cast state and after measurement showed dendritic structure. Structure of magnesium alloys AZ91 was carried out after the homogenization annealing at temperature 390 °C. It was also used application of mathematical calculations for a more accurately experimental measurement of internal friction depending on the temperature.

The article deals with cyclical abrasive wear of the surface of forming tools. At this stage the research focused on the genesis of stress in the contact between a deformed material and a tool in the cold bulk forming process. The experiments were conducted in the simple configuration of the upsetting test. The article presents the results of abrasive wear by a combination of materials of examined samples and upsetting plates. The abrasive wear in the used material specimens was analysed comparatively in the form of the wear factor by the finite element method. Two intersecting phenomenological fields represent the output for the examined material combinations. Firstly, it is a formulation of the dependencies of the maximum depth increase of the surface wear. The argument is the number of exposure cycles. At the same time, the topology of degradations and the resulting roughness in the space of the exposed surface were examined.

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.

Metal-plastic parts with steel inserts prepared by overmolding technique showed several cracks. Cracks marked as no 1 and 2 were noticed immediately after overmoulding process. Cracks no 3 and 4 were propagated only several days after overmolding, during post crystallization of plastic. The superposition of both high residual stresses at the metal-plastic interface and creation of cold joints in overmolding plastic were the reasons of cracks initiations. Residual stresses at the metal-plastic interface exceeding the yield strength of plastic were confirmed by simulation in Moldflow software. The differences in the melt front temperature above 20 °C were simulated in the critical areas where the cold joints created in the real metal-plastic parts. Cracks no 1, 2 and 3 were eliminated by increasing of plastic thickness in the critical areas. Cracks no 4 were eliminated by decreasing of packing pressure, what also contributed to the elimination of cracks no 3.

Article deals with the detection of reduced stress in a braked railway wheel based on thermal transient analysis on virtual models, because they influence the characteristics of the railway wheels. Structural analysis was performed by means of the ANSYS Multiphysics program system package. Thermal transient analysis deals with the detection of temperature fields which are result of braking by brake block. The applied heat flux represents the heat generated by friction of brake block. It is applied to the quarter model because of the acceleration calculation. This analysis simulates two braking with subsequent by cooling. Distribution of the equivalent stress was detected in the cross section railway wheel, at selected points. The input parameters were used from the thermal transient analysis. These equivalent stresses result due to thermal load.

This article is aimed at studying the impact of surface integrity - surface roughness, hardness and residual stress - on fatigue performance of EN S355J2 steel. The test specimens were manufactured by turning. A longer fatigue life for the machined components can be obtained by applying such cutting conditions as a low feed rate. The fatigue limit of the specimen with the surface roughness Ra 1,6 μm is approximately 7 % higher than that of the specimen with Ra 3,2 μm. From the residual stress results it can be seen that the cutting conditions used for producing surface finish Ra 1,6 μm will introduce mainly compressive residual stress whereas the cutting conditions used for producing surface finish Ra 3,2 μm will introduce tensile residual stress. The measurements were carried out at Aalto University at the Departments of Engineering Design and Production and Material Science and Engineering in Espoo. The main purpose of the study is to find proper surface finishing techniques and fatigue improvements for hydraulic components.

The quantitative and qualitative results of the technological process are mostly determined by the level of finishing operations, which include particularly the grinding. It is characterized by high precision, the accuracy of geometric shape and generally a very good quality of surface. One of the factors to achieve the desired quality of the finished surfaces is in particular the knowledge of the effect of temperature of the contact surface of the grinding wheel and the ground piece. The article specifies the methodology of quantification of the impact of cutting parameters on the temperature of the grinding. Another requirement is the proper choice of other cutting parameters to guarantee the achievement of the required accuracy of dimensions and shape, increased performance and reduction of the contact temperature between the ground surface and the grinding wheel.

The shaping tools or shaping moulds are applied in such production processes like forging, pressing, casting or injection moulding. These technological processes are described by Groover in [1] and Kalpakjian in [2], as well as in the other professional works, e.g. in [3, 4, 5]. A quality of the shaping tools influences also quality of the produced components. This fact is an important aspect in the framework of the whole production chain.The shaping tools and moulds are expensive. An important role is playing the selected production technology of the given shaping tool. If there are applied machining technologies specified for production of the shaping tool, it is necessary to take into consideration also the suitable machining strategies for such technological operation. The term "machining strategy" represents a pre-definition of such tool trajectory in the CAM-system, which is optimised for machining of the various shaped surfaces in order to produce the final product with the highest possible efficiency.[5]

This paper describes a method of ABS-aramid composite material production by Fused Deposition Modeling Rapid Prototyping System. In the beginning there is presented common technology of parts production by Fused Deposition Modeling method of Rapid Prototyping. Then it deals with the theoretical description of proposed concept production of ABS-aramid composite material by Fused Deposition Modeling method. In the main part it describes an experimental testing of proposed concept at the Faculty of Manufacturing Technologies in Presov in the laboratory of Rapid Prototyping. For creation of sample bodies using the FDM method of RP we used the combination of basic ABS material reinforced by aramid tissue. At the end it summarizes possible trends of further development and research in described area together with possibilities of industrial applications.

Nowadays the pressure to increase the efficiency of the machining processes is constantly growing. The efficiency of the machining process can be pursued from two basic perspectives - enhancing the cost-effectiveness of the process (decreasing production costs) or increasing production in time. Via these approaches alone, manufacturers of parts as well as suppliers of machine tools and cutting tools try to improve their position in a highly competitive market. One of the approaches to increase efficiency is the correct choice and subsequent optimal exploitation of the potential of cutting tools and machine tools as well as a reduction in the energy intensity of the cutting processes for a given component. That is what led to the idea of creating an analytical-material model for determining the force interaction between the cutting tool and workpiece, energy intensity and machining process efficiency. The result will be an application that helps technologists in practice to choose correctly the appropriate types of cutting tools, operations, machine tools and also quickly determine the main parameters of the cutting process so that there is the possibility of comparing their results with other variants. The first step and goal is to create an overview of the cutting processes and the associated cutting process modelling, compare their advantages and disadvantages, and then propose an approach of our own.

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.

Springback of v-type sheet metal must be controlled during the high precision forming process. While, variable blank-holder force technology is an effective measure to control sheet metal springback, but it only overall control the stampings. The project was put forward through the v-type sheet's variable blank-holder force and adjustable drawbead to control springback, which is place electric adjustable step drawbead around the blank-holder. Changing the blank-holder force, meanwhile, adjusting the height of the drawbead according to the needs of the stamping real time, so as to control the quality of sheet forming. To get the optimal combination of variable blank-holder force and adjustable drawbead, this rearch for the technology to control the springback, which has carried on the theoretical analysis and numerical simulation, then providing test for it.

The paper deals with the practical use of matrix model of sustainable development, the MSD (Matrix of Sustainable Development) in Industrial Management and an introduction to possible problems in implementation. The method is based on expert evaluation, the output of the relational matrix are values of importance, resp. the overview of the priorities of the problem, i.e. the individual social requirements and the factors of quality products. The implementation of the MSD model contributes to the holistic understanding of the product's life cycle. The results reveal the model on the one hand in it is the real importance, and, on the other hand, the possible shortcomings of some hitherto unknown factors. The benefit is also involved in research in the field of quality management and a focus on customer requirements.

Article is focused on detection internal residual stress caused by machining with variant spindle speed of milling tool and also in the article is represented new method of residual stress measuring using by ultrasound with verification method using RTG diffraction. Effect of residual stress have in industry important place because large number of structures requires a clearly described process of the occurrence and intensity of internal residual stresses, which directly affect the quality and equipment life. Nowadays are mostly used destructive methods, which can occur changes in functionality of the products or non destructive methods are used, which require to measure residual stress outside of the workplace and those methods are often lengthy. In the article is presented new method base on ultrasound, which provides opportunity to measure residual stress in same place in a short time.

The soil is a considerable abrasive medium which exerts on tools processing the soil in a negative way. The main problem connected with using the soil processing machines is their wear owing to particles embedded in the soil. The ploughshare is one of the most loaded parts of the ploughing body and huge requirements are put on it. The aim of the research is to set an angle of a soil flow and connected wear of the ploughshare at the traditional processing of the soil. It is possible to further issue from ascertained pieces of knowledge at a production/renovation of the ploughshares with new functional surface. The statistical analysis evidenced that the angle of the soil flow on the ploughshare surface was the same with the angle of the ploughshare head. It followed from the measurements that the optimum angle for depositing the oblique overlay which is necessary for the creation of the serrated edge is in the interval 35 ± 4°.

Paper deals with the machining of super-hard ceramics by turning. The introductory part deals with analysis of used ceramic materials and their use in technical practice. Since it is a very hard technical ceramics and particularly resistant material, at present, is increasingly used to produce components that ensure long life and particularly high resistance, even in aggressive environments where metal materials can no longer be used. Products from ceramics are pressed and sintered directly to the desired shape, but in some cases they have to be machined, which technically can cause a problem. The aim of the experimental part is selection of suitable cutting insert, determining of cutting conditions that would ensure the productive machining of given ceramics. Work may serves as a troubleshooting support for machining ceramics.

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).

It is necessary to study and master the springback rule of single point incremental forming of magnesium alloy on different process parameters, which has important theoretical and practical application value to complement and perfect the springback control technology of single point incremental forming of magnesium alloy. Taken the variable angle truncated cone as the research object, used the ANSYS/LS-DYNA as research tool, viewed the springback amount as research criteria, the influence of different process parameters to the springback of single point incremental forming is studied in this paper, which includes forming temperature, friction conditions and tool diameter. The results show that the springback could be effectively controlled when the forming temperature is 250℃, the static friction coefficient is 0.2, the coefficient of kinetic friction is 0.1 and the diameter of the tool is between 10mm and 12mm.

The paper dealt with method of immediately cutting process stoppage, process of chip formation and the non-linear finite element analysis. To be able to follow the process of chip formation and machined surface during machining, it is necessary to stop this process immediately, if it is possible. The paper provides results of non-linear numerical experiment for presented method. The state of plastic deformation in machined material and in front of the tool cutting edge enables to follow the intensity of deformation, friction process between the tool, chip and workpiece, sources of heat in the machining zone. Knowing these processes enables to select optimal tool geometry, cutting conditions, mainly cutting speed, cutting environment, tool material so that cutting process could run with minimal energy consumption and required quality of machined surface could be reached. To understand the process of chip formation is important for the theory and practice of machining of materials.

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.

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.