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Secondary cast alloy AlZn10Si8Mg (UNIFONT-90) is generally used for engine and automotive constructions, hydraulic unit and mold making without any additional heat treatment. It has good properties such as castability, very good mechanical strength, light weight, good wear resistance and very good machining. At present, one of the main limits to a wide use of aluminium alloys for engine or automotive applications is a lack of complete understanding of their fatigue behaviour and of the relationships to microstructural features, particularly as far as casting alloys are concerned.
Fatigue properties of AlZn10Si8Mg cast alloy in the high-cycle cycle region were tested by rotating bending fatigue loading with the used of parameters - frequency f = 40 Hz, temperature T = 20 ± 5 ℃ and stress ratio R = -1. Numerous studies shown those cast aluminium alloys are very sensitive to casting defects as porosity and microshrinkages and whenever large pore is present at or near the specimen's surface, it will be the dominant cause of fatigue crack initiation.

Wire electrical discharge machining (WEDM) is an unconventional technology of machining that uses physical phenomena for material cutting. During wire electrical discharge machining craters are formed on the workpiece surface, and blended and molten material of both workpiece and wire electrode get stuck here due to diffusion processes. The study deals with the assessment of the influence of wire feed rate on quantitative and qualitative evaluations of craters on the workpiece made of X155CrVMo12-1 alloy tool steel. The diffusion phenomena that had occurred on the surface during the process of cutting were studied using light microscopy. Attention was also given to the detail study of the used brass electrode where the level of wear and degradation in terms of the quality of morphology were studied after the process of cutting.

This article deals with the benefits of PVD coatings ((Al,Ti)N; (Al,Ti,Cr)N and nanocomposite coating nACo®) applied to HSS three edges end milling cutters (producer ZPS - Frezovaci nastroje, Zlin, CZ). The coatings were synthesized by a cathodic-arc deposition process (producer Liss, Roznov pod Radhostem, CZ). Machining was carried out on the vertical milling machine FB 32V with using process liquid. Set up cutting conditions were constant throughout the machining. The aim of this experiment was to compare coated and uncoated HSS end milling cutters and find out the benefits of three kinds of PVD coatings. The monitored parameters were force loading and flank wear. Piezoeletrical dynamometer Kistler 9257B was used for measuring force loading and workshop optical microscope was used for measuring flank wear (criterion VB). The construction steel C45E (1.1191; CSN 41 2050) was used as workpiece material. Best results were achieved by tool with PVD coating (Al,TiCr)N.

The article deals with the machining of glass fiber-reinforced thermoset composite. Emphasis is placed on the selection of cutting tools for end milling. Experiment involved slot milling by special tools for composite machining with different geometries and surface coating. Further, the quality of the machined surface, cutting performance, dimensional accuracy, delamination factor and tool wear were evaluated. The results were compared with the end milling of carbon fiber-reinforced polymer composites.

The present contribution represents the analysis and optimizing management of the measurement system of the technological process of pressing. It has been chosen the combination of appropriate methods for achieving the objective to minimize the cost of quality assurance of the measurement process by means its management. The quality of the measurement process has been verified by the reference standard (etalon). The optimization of evaluation measurement has been searched by utilizing QFD method (Quality Function Deployment). The subsequent optimization has been implemented by the taking into account the results of the use of the control charts and the deployment of QFD method and Kalman filter.

The present paper expands the knowledge in the field of welding of age hardening aluminium alloys using MIG method. Aluminium alloy AW 6082 (AlSi1MgMn) according to the specification standard CSN 42 4400 was used for the experiment. This type of alloy is used in industrial practice e.g. for medium stressed parts in railway and motor vehicles and in water, oil or petrol pipes. For the purpose of assessing the impact of multiple cycles on the properties in the heat affected zone the weld was designed as a multi-layer weld. The objective of this paper is not only the impact assessment of the degradation of the mechanical properties, but also the possibility of recovery of these properties by heat treatment. During the experiment, the effect of temperature holding time by solution annealing and artificial hardening on the mechanical properties of the base material, HAZ and weld was studied. The effect of heat treatment was evaluated by Vickers hardness test.

This paper describes research in technology of the heat treatment for tool steel Böhler K455 designed for cold work. The aim of the research was based on operational experiments to draft procedures for heat treatment of the tools in a vacuum hardening furnace. Testing of two alternative methods and comparison of the state of microstructure and the mechanical properties with the current state of these indicators of dies quality will highlight the importance of introducing innovations to achieve higher lifetime of dies and the justification for the purchase of new technological equipment.

Ti-Al-Si alloys are very prospective materials for many applications, particularly for automotive and aerospace industry, due to their low density, excellent resistivity to oxidation and heat stability. The main problem is high brittleness at room temperature and high mechanical characteristics persisting only up to 800 °C, which is limiting in some applications. Ti-Al-Si alloys were prepared by powder metallurgy using Self-propagating High-temperature Synthesis (SHS), which is considered as a first step in production consisting of SHS, milling and consolidation by Spark Plasma Sintering. In this experiment the observed subject was the microstructure and phase composition of Ti-Al-Si alloys in order to find optimum alloy composition for desired technology. Based on the results of this work, TiAl15Si15 alloy can be recommended due to fine microstructure composed of titanium silicide (Ti5Si3) particles in the matrix of titanium aluminide (TiAl). Concerning the production by SHS, the highest achievable heating rate can be recommended.

A mechanical treatment of an adherent before an application of adhesives is one of key factors influencing resultant strength of an adhesive bond. A grit blasting belongs among one of the most often used methods of the surface treatment. A resultant structure of blasted adherent and also parameters of the surface roughness can be changed during the blasting by a suitable choice of many parameters among which a material and a size of abrasive particles, a distance of an air jet and a blasted material, a size of the jet, an air pressure and an angle of abrasive particles impact can be ranked. This experiment describes an injector system of grit blasting using basic abrasives - corundum and glass ballotini. During grit blasting of common steel adherent it came to the change of the impact angle of the abrasive particle in a range from 75° (a perpendicular angle) to 10°. Different impact angle led to different roughness parameters and to various structure of the adherent surface which was evaluated by an electron microscopy. Subsequently, it came to experimental description of the strength of adhesive bonds which were created by adherents whose surface was grit blasted under various impact angles of abrasive particles.

Rare earth elements in magnesium alloy enhance mechanical properties, corrosion resistance, and heat stability up to 300 °C. Those enhancements with low density of magnesium determine this alloy for aviation and automotive industry. Magnesium alloys are also considered as materials for biodegradable implants. In this field there are required good mechanical properties and fair corrosion rate. In this work, WE43 alloy prepared by powder metallurgy with different conditions of sub-processes is prepared. Milling, cold uniaxial pressing, spark plasma sintering (SPS) and extrusion processes are used for sample preparations. Structure and mechanical properties of prepared materials are characterized.

Aluminium castings have played an integral role in the growth of the aluminium industry since its inception in the late 19th century. The Al-Si-Cu alloys are the most versatile materials, comprising 85 - 90 % of the total aluminium cast parts produced by the automotive industry due to their highest strength to weight ratio, good thermal conductivity, excellent fluidity, hot tear resistance and feeding characteristics which allow casting intricate shapes such as engine blocks, cylinder head sore chassis components and so on. Whereas these parts are made by casting the porosity evolution is important, in order to secure the best mechanical properties of these casts. Therefore this work is focused on evolution the porosity in Al-Si-Cu cast alloys using light metallography microscopy and image analyser software. The evolution shows that the experimental material casted into the metallic mould had about 98.78 % smaller porosity size in comparison to the material casted into the sand mould, therefore it showed better properties.

Grinding operations are sometimes replaced with hard turning or milling cycles. Mechanism of chip separation during grinding and the corresponding surface integrity remarkably differs from hard turning or milling. For this reason, this paper deals with application of Barkhausen noise for evaluation of surface anisotropy after hard milling. Experiments were carried out on bearing steel 100CrMn6 hardened on 45, 55, 62 HRC and one series without heat treatment. The analysis contains comparison of RMS values for the different hardness and tool wear after hard milling and also discusses the specific mechanism of BW motion in the case of cyclic magnetization.

Self-hardening secondary Al-Zn-Si-Mg alloys represent an innovative class of light Al-Si alloys. The most important and relevant feature of the self-hardening alloys is related to their good performance, without the need of any heat treatment. Mechanical properties depend upon the morphologies, type and distribution of the phases. It is therefore important to study the intermetallic phases occurring in the secondary Al-alloys, where they found more than in the primary-Al alloys. Study of intermetallic phases in the alloy was performed on an optical microscope using classical etching technique (by 0.5 % HF) to invocation black-white contrast as well as unconventional methods for invocation colour contrast (etching by Weck-Al) to the observed surface of the sample. The colour metallography results were correlated with the information obtained by standard etching. The microstructures of the samples were analysed by scanning electron microscopy after standard etching and deep etching (with HCl) too. After deep etching we are able to see the 3D morphology of eutectic Si particles and intermetallic phases.

To design an optimal support of a large shade sail it is necessary to determine forces in wire ropes that support the sail. Relations between a sail loading and ropes reaction forces, rope diameters and sail stresses were investigated. To simulate the sail behavior and set up these relations, numerical (FEM) models were created and analyzed. Most of the results show nonlinear relations between above mentioned parameters and they depend on the sail geometry, applied loads and the rope diameter. It means that for every specific geometry and loading of particular sail an optimal rope diameter and support should be designed. The nonlinear numerical analysis is very suitable tool for this purpose and thus specialized systems based on the Finite Element Method (FEM) should be used to simulate and analyze such problems.

This paper investigates the influence of Artificial Neural Network (ANN) architectures on its prediction capability when machining nickel based super alloy. The ANN was employed to determine surface roughness parameter Ra through cutting conditions, tool wear and process monitoring indices such a cutting force components. The ANN structure was optimized by methods like a reduction of input vector parameters, dimensions of input data pattern, combined reduction and modification of hidden layers. Calculated and experimentally measured values were compared for each optimized ANN model. The work concludes that optimization of ANN has significant influence on prediction capability and accuracy for the task proposed.

Existing models of predict the abrasive water jet cutting effects, does not give satisfactory results in a wide area of parameter changes, in particular for different, exotic materials. This implies the need to carry out extensive research in order to expand the empirical database. To optimize the process can be used modern methods referred to as Design of Experiment. One of the methods to determine the effect of parameters on the controlled different technological processes is the Taguchi approach. This method allows to limit the amount of research needed to achieve the desired test results, reducing the time required course for their performance and at the same time their costs. Characterized by Taguchi ratio signal / noise (S / N) enables the assessment of the significance of the impact of various parameters on the process, which is still not well enough understood. The article discusses one method for optimization of cutting tool steel, by high pressure abrasive water jet.

This article deals with simulations of the welding process for applications of practice using SYSWELD software. Simulation of welding at the repair of high-pressure gas pipeline with steel sleeve with composite filling is presented in this paper. Two welds connecting the distance ring and gas pipe were simulated. Structure of programme SYSWELD and repair of high pressure gas pipeline with steel sleeve is described in theoretical part of article. Preparation of boundary conditions for numerical simulation on real sample and numerical simulation of welding is in experimental part. Thermal fields, residual stresses and hardness were simulated. The results of the numerical model, which are listed in article except for residual stresses are compared to real experiments. This article mainly describes the numerical simulation capabilities in welding simulation programme SYSWELD.

Within the research, an attempt was made to determine influence of preliminary wetting of high-silica based eco-friendly moulding sands containing sodium water-glass on effectiveness of their hardening by traditional drying. Effectiveness of adding water to the base during stirring was evaluated by comparing mechanical and technological parameters after traditional drying at 100 °C. Medium high-silica sand and two grades of hydrated sodium silicate 149 and 150 were used in the examinations. It was found that modification of preparation procedure by adding a proper quantity of water to high-silica base before adding binder (1.5 wt%) favourably affects mechanical and technological parameters of hardened sandmix. Results of the measurements are correlated with SEM observations of links between base grains. On the grounds of complex evaluation of moulding sands hardened by traditional drying, a positive effect of water addition was found, especially in the sandmixes containing binder with higher viscosity, i.e. grade 149. Optimum quantity of water addition should be determined for each specific grade of binder.

This work deals with an impact of abrasive particles used in powder injection molding (PIM) on a surface roughness of the tool. For this purpose, the surface of new mold cavity was compared with the same mold cavity after 2 000 injection molding cycles. Processed PIM compounds contained polymeric binder with around 60 vol. % of metal or ceramic particles (0.1 up to 20 μm). Surface analysis was performed on cavity impressions prepared from a special silicone imprinting substance in two directions by a 3D surface scanner. Investigated parameters were surface roughness (Ra) and roughness depth (Rz) which have an influence on flow instabilities of highly filled compounds such as wall slip affecting the final product quality. Obtained results showed a significant wear of the mold cavity which was statistically confirmed by t-test and F-test parametric methods. A greater part of the mold cavity was smoothed during injection of PIM compounds, while the surface roughness increased near the point gate (runner system) probably due to a high injection pressure in this part of the mold.

This paper deals with the assessment of the procedural gases progressive cooling methods and cooling by procedural liquids at turning technology on the final workpiece surface quality. Turning by using liquefied CO2, liquefied nitrogen and subcooled air supplied through the vortex tube was compared with the turning without process medium (taken as reference conditions) and with two procedural liquids EOPS 1030 and HOCUT 795 B. At evaluation effect of procedural gases there were monitored acting forces, cutting tool cooling rate and the machined layer of the material, cutting tool durability and cut surface quality which was characterized by surface roughness and dimensional accuracy. During the experimental part there were used devices as lathe SU50, piezoelectric dynamometer, the evaluation unit and profilometer. This issue was solved within solving the project TACR - TA03010492.

The purpose of using modern technology is to reduce costs, facilitate the work and simplify as far as the most comprehensive set of operations. One of many modern technological processes involved in the refining of materials are technologies of surface hardening using a laser beam. This method can harden precisely defined areas with minimal thermal influence of surrounding areas it is possible to achieve less residual stress and less distortion of components compared the volumetric hardening, it is also possible to use controlled robotic units and all for the absence of cooling, which proceeds spontaneously to the surrounding material itself and atmosphere. These advantages of laser surface hardening are used by companies for which the prospect of minor damage to the material, increase of the material durability, material stiffness ensuring etc. is initiation for the use of modern technology.

In the report the results of bonded joints laboratory tests are published. The determination of the tensile lap-shear strength of rigid-to-rigid bonded assemblies according to the standard CSN EN 1465 (66 8510) was the aim of the carried out tests. The samples were made from steel sheets. For bonding of test samples four different types of adhesives were used (two super glue adhesives, one epoxy adhesive and one contact adhesive). Ahead of bonding the surfaces of all samples were blasted using corundum grit and degreased. For degreasing four various types of five different degreasers were used, namely perchlorethylene, acetone, methanol, technical gasoline and toluene. Then the samples were dried using warm air. For comparison the blasted samples without degreasing were bonded, too. At the tested samples bonding the consumption of adhesive was determined. From the adhesive consumption for one bonded joint and from the adhesive price the costs of one sample bonding were calculated. After curing the bonded assemblies were loaded using the universal test machine LabTest 5.50 ST up to their rupture. The rupture force was written down. From the values of the rupture force and the bonded surface size the bonded joint strength was calculated. By the carried out tests evaluation the influence of different degreaser types was determined. Also for all used adhesives the price of one bonded joint was calculated.

The aim of this work was studying the effect of the composition and production on mechanical and tribological properties of cobalt alloys. Co-Cr-Mo alloy began to be used for manufacturing dental implants, but nowadays they are successfully used for the production of orthopaedic implants thanks to better wear resistance than is offered by titanium implants. However, there is still ongoing effort to even more improve the wear resistance and other properties of cobalt based alloy. The aim of this research was to find a suitable combination between composition and production, which would increase the wear resistance, keeping the other mechanical properties at least at the same level. Standard Co-Cr-Mo alloy and also Co-Cr-Mo alloy with various alloying elements, specifically Nb, Ti in an amount 5 wt%, were prepared by casting and also mechanical alloying followed by compacting method "Spark Plasma Sintering". The influence of production route as well as influence of alloying elements on the microstructure, mechanical and tribological properties were observed. Based on the obtained results, the Co-Cr-Mo-Ti alloy production by casting seems to be most suitable, because the addition of titanium has greatly improved the wear resistance. However, it is necessary to perform many other tests, especially tests of corrosion resistance and biocompatibility.

Titanium is widely used as biomaterial due to its excellent corrosion resistence, caused byTiO2 layer that is spontaneously formed on its surface, biocompatibility and good osseonitegration ability. To approach mechanical properties to human bone there is increase of using porous titanium. That form has lower density, causes better ingrowth of bone tissue which makes a strong bond between implant and bone. Porosity also decreases Young's modulus, which causes that the "stress shielding" is eliminated. New alloys based on titanium and silicon seems to be a perspective material for biomedical applications. This work is devoted to the optimization of the alloy composition and the addition of the pore-forming agent. It has been shown that this alloy can achieve the mechanical properties and microstructural features comparable with the human bone.

NiTi is a shape memory alloy used mainly in medicine. Many applications can be also found in industrial sector. Its properties are considerably determined by structure and phase composition. It was found that production by powder metallurgy method leads to creation of required phase NiTi, but certain amount of hard and brittle phase Ti2Ni is also formed. Its presence in the structure affects mechanical properties of the alloy and it might widen the applicability of material to a new industrial branches. Suitable preparation method of composite material NiTi-Ti2Ni with the possibility to control amount of generated phase Ti2Ni would allow regulation of material mechanical properties.

This article offers a novel method of gold nanoparticles preparation which increases their obsevation feasibility. Gold nanoparticles were prepared by sputtering of 6 nm of gold on surface of NaCl crystals and consequent annealing. Gold nanoparticles were separated from the substrate mechanically in the ultrasonic bath. The preparation of gold nanoparticles on NaCl substate is extremely versatile. It enables to descibe size and shape of the individual nanoparticles much better than usually used SEM and AFM techniques, it enables to see the lattice arrangements and also to do more precise chemical analysis without the influence of the substrate. It is applicable for characterization of temperature-, time-, chemical composition- and atmosphere influence on morphology of gold nanoparticles. The nanoparticles were observed by HRTEM. In our case, the influence of carbon addition on morphology of gold nanoparticles was studied by sputtering one or two carbon interlayes in the gold layer. It was found out that one carbon interlayer slightly descrease nanoparticle size. On the other hand, two carbon interlayers lead to formation of irregular large shapes of the gold particles.

In this work, the influence of alloying elements on the transformation temperatures and temperatures of formation of NiTi intermetallic phases were investigated. NiTi alloys are characterized by shape memory effect, pseudoplasticity and superelasticity. These properties strongly depend on the alloy composition in binary Ni-Ti and ternary Ni-Ti-X. Because these alloys are used in various branches of industry, such as aerospace, engineering or medicine, the addition of ternary element can influence their application significantly. Especially, the presence of Ti2Ni and Ni3Ti in the NiTi matrix may cause a degradation of the shape memory behaviour and mechanical properties. For this reason, we observed the formation of intermetallics by differential thermal analysis (DTA). Differential scanning calorimetry (DSC) experiments were performed to monitor the evolution of the transformation characteristics. We report new results, which show the strong dependence of the transformation temperatures between austenite and martensite on the alloy composition, and how the alloying elements (Mg, C, Zr) influence the formation of Ni-Ti phases.

Accuracy of work-pieces of complex free form surfaces is achieved by tolerancing, producing and metrology of workpieces. The tolerance zone is defined by form tolerances, their orientation and location on the work-pieces. Tolerances for complex form surfaces are specified by line profile tolerance or surface profile tolerance. These tolerances control form or combination of size, form, orientation and location. In a machining process the impact of machining parameter settings on the final surface quality will be researched. The influence of toolpaths in connection with the SH (Scallop Height) parameter setting on production accuracy and quality of machined surface will be compared. For geometry verification of the complex form surfaces are coordinate measurements used. The measurement area is modeled with the equations in CATIA V5. The data of machined surface obtained through the contact coordinate measurement are processed using the coordinate system adjustment via the RSS minimization by the Newton method in Matlab/Octave. Calculated values of surface profile deviations at individual machining strategies are used to achieve the required quality of machined surface through optimization of the machining parameters.

This essay aims to describe technology and mold design for production of hollow composite parts like carbon rims or sport rackets. Tested materials correspond to those used for composites in sport applications. Production technology called inflatable bladder molding (IBM) is describe with respect to used material, molds and process parameters. Furthermore, prototype mold for verification of flexible bladder, inner pressure and curing conditions is constructed and tested. Construction design of manufacturing mold together with description of technological steps is proposed.

The cab of the big-scale and medium-sized agricultural machinery is not only the main environment of the drivers operate the machine, but also by which the driver interact with the machine. Currently most China's agricultural machinery manufacturers will order the whole cabs for production, but not make them by themselves. Therefore to design the cab models by parametric customization would be better adapt to business needs and reduce the repetitive and mindless calculation and design. The design of cab mainly includes two types of parameters: the driver's ergonomics data and the constraint parameters provided by agricultural machine such as space area, etc.. In addition its shape should match the the whole style of the machine. The paper provides a parametric design procedure of cab's frame based on RhinoScript. Firstly the characteristics of a variety of cabs are analyzed and classified into several typical sorts; then the main ergonomics parameters and constraints of these cabs are extracted; finally the basic framework of the cab can be automatically completed on these data and constraints and a digital model can be generated by the chosen style of the agricultural machine.