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The effort to increase the rail vehicle ride speed on existing tracks, or more precisely on modernized tracks with a lot of curves with a relatively smaller radius, lead to use of tilting mechanism of the vehicle body. The paper deals with simulation analysis of a rail vehicle with an active tilting system of the vehicle body, design of the rail vehicle in CAD program CATIA and dynamical analysis in program SIMPACK, with the RAIL expansion. Such body mounting on vehicle bogies is significantly more complicated than the design of conventional rail vehicles. The purpose of this type of body mounting is to increase the size of body tilt during ride in a curve and thus reduce the lateral unbalanced acceleration affecting the passengers, or allow higher driving speed in a curve with the same radius while keeping the lateral acceleration value respectively. Eight variants of different velocity, vehicle occupancy and setting of the tilting mechanism were analyzed. We determined the average value of passenger comfort NMV from the simulation results. We have determined the value of passenger comfort during the ride in a curve PCT from the simulation results.

CuZn brasses are used for manufacturing highly stressed structural comonents. Their mechanical properties as e.g. strenth, toughness or wear resistance are affected not only by their chemical composition, but also by their structure. This paper is dedicated to the study and comparison of the structure of sand- and metal mould casted Cu40Zn alloy. Scanning electron microscopy supplied by energy dispersive spectroscopy and electron backscatter diffraction were used to evaluate the structure of both samples. Casting into the metal mould produces approximately five times finer grain structure compared to the sand mould. EBSD orientation mapping revealed a strong correlation between both matrix phases, αCu and β' phase. Also, the size of Fe2MnSi ternary precipitates is affected by the cooling rate.

Firefighter ladders are manufactured of aluminium alloy AA 6063. These ladders are a widely used technical tool for firefighting, for intervening firefighters and for rescued persons. The quality of the ladders is checked by so-called "user test" which is a non-destructive deflection test defined by CSN EN 1147. Unfortunately, this test is not sufficiently conclusive in terms of safety. Therefore, the project called "Safety improvement of extension ladders for firefighters" (VI20162020021) is focused on the complex assessment of the existing firefighter ladders through mathematical modelling, material analysis and real testing. In the present work structure and mechanical properties of samples (aluminium alloy AA 6063) taken from different areas of a firefighter ladder are presented. The obtained result confirm excellent mechanical properties of selected samples, such as tensile yield strength and ultimate tensile strength, at laboratory temperature but a huge decrease in these properties after exposure to temperatures above 200 °C for even short times. This results in the necessity to control temperatures in the proximity of the ladder, especially in the case when the ladder is located near a flame.

This paper describes the conception of vehicle interior which can help decrease the injury risk of unbelted passenger. This paper is primarily aimed to the field of rail vehicles, but the results are useful for more transportation industries. Some computer simulations for passive safety performance assessment were conducted in previous years. The FE models of the interiors based on data from actually operated vehicles were prepared for this purpose. The newly prepared simulations are close to the real interior models. Combinations of rigid walls were used for modelling. Each model contains a short python code which allows change of interior disposition. This approach is close to an optimisation process. The main goal is to compare all possible configurations of interior. In practise it is usually obvious which change can improve the passive safety, but with numerical approach is possible to find structures with unknown influences. The simulations were performed in software environment PAM-CRASH. It is used a dummy Multibody model of the human body ARB Hybrid III 50th percentile.

The article describes the course of a pressure test that was made to determine the maximum force in the case of breaking the integrity of the casting. Observation of the forks arm deformation can be done with using sensors on the universal tensile testing machine. Using a high-speed camera to monitor this test will provide results in digital form that can serve to further research. Subsequently, analysis of the material properties of the AlSi7Mn0.3 casting is described, using the methods of evaluation of mechanical and structural properties. Periodic tests check the castings status to ensure recurrent quality in order to achieve the required safety in accordance with the standards for road vehicles.

The paper deals with the monitoring the metallurgical purity of alloy AlSi9Cu3(Fe) both in the dependence on the input material quality and on the manner of the melt metallurgical treatment. Experiment was divided into two phases. During the first phase there was monitored the metallurgical purity of the input material delivered from the different suppliers. During the second phase was at the standardly prepared melt observed the influence of the degassing time on its metallurgical purity. To evaluate the input material metallurgical purity, Drosstest was performed and subsequently also the metallurgical evaluation of samples. To determine the influence of degassing time on the metallurgical purity of melt, Density index (DI) was monitored. By this index it is possible to evaluate the amount of inclusions and dissolved gas. Based upon the measured values there was determined the degassing time needed to achieve the required values of DI.

Magnesium alloys are utilized in automotive and aviation industry due to their low density and good mechanical properties. However most magnesium alloys lose mechanical properties at high temperature. Another weak point of magnesium is its high corrosion rate. Alloying by rare earth elements improves mechanical properties, corrosion resistance, and heat stability up to 300 °C by formation of intermetallic phases. Further improvement of corrosion properties can be achieved by coating. Fluoride conversion coating is ideal for magnesium alloy due to its low thickness, good adhesion and easy preparation. In this work, WE43 alloy prepared by extrusion is immersed in hydrofluoric acid to obtain fluoride coating. Extruded pure magnesium is immersed the same way as WE43 for comparison. Surface and cross section of prepared coating and corrosion properties of prepared materials are characterized. Fluoride conversion coating decreased corrosion rate by one order of magnitude for pure magnesium and by half in case of WE43 magnesium alloy.

Plastic injection process is one of the techniques used to manufacture plastic products. The technique is widely used due to its higher and faster production capacity and low cost. However, production process problems are often found, one of which is inappropriate process parameters settings, which may cause product defects. This paper presents a method using combination of Taguchi method, Moldflow simulation and PSO to optimize plastic injection molding process parameters. Moldflow simulations were run to obtain volumetric shrinkage values resulting from each combination of parameters setting selected by means of OA. In adopting S/N ratio technique of the Taguchi method, the study adhered to the principle of "the smaller the better". The ANOVA method was also used to analyze the effect of each process parameter on volumetric shrinkage and a regression analysis was used to establish the equation used for the application of the PSO method to optimize plastic injection process parameters. This method was applied for the production of number plate brackets from PP AZ564 material. The study concluded that the application of the combined Taguchi-Moldflow-PSO method could reduce volumetric shrinkage from 6.05% to 4.24%.

Cr-Ni stainless steels are commonly used for construction of various equipments exposed to halides containing media, which can act aggressively and cause a serious local corrosion damage of these materials. This article focuses on the resistence of AISI 304 stainless steel to the pitting corrosion in 1 M acidified chloride solution represented by mixture 0.9M NaCl + 0.1M HCl, at the ambient temperature of 22 ± 3 °C. An evaluation of the pitting corrosion resistance was based on the cyclic potentiodynamic polarization tests performed on three types of steel surfaces: "as received", electropolished and ground + electropolished surfaces. The pitting potentials were determined and compared. Pitted surfaces after potentiodynamic polarization tests were observed by the optical microscope.

An article deals with a production of a planetary mechanism model prototype using an additive method of Rapid Prototyping (RP) by a 3D printer called uPrint. The first part of the article contains a theoretical analysis of a main principle and kinematics parameters of the planetary mechanism model. The second part begins with an experimental analysis of a planetary assembly calculation and continues with a description of a production process of all individual mechanism parts and description of the final completing of the planetary mechanism prototype. The final part deals with a characterization of ABS styrene polymers generally used for production printed by uPrint device.

In a competitive market the manufacturing companies have to produce cost effective products which can be realized by minimized production cost and higher effectiveness. The application of Lean manufacturing philosophy in order to optimize costs and quality is gaining a competitive advantage. There are lots of Lean tools which can result the improvement of the production line performance.
The article is original and unique, because beside the description of theoretical background relating to the process improvement, a practical method is also introduced in a case study.
In the study the author describes the main general steps of a Lean project completed in an industrial environment. The described case study which is a part of a real R+D project shows how can be improved the efficiency and reduced manufacturing cost of a real manufacturing system by application of several Lean tools which are One-piece flow, Takt-time analysis, Line balance and Cellular design.

In present paper, the growth process of the phosphate coating on S355J2 steel was investigated. The microstructure, surface morphology, coating thickness, surface roughness and corrosion resistance of the phosphate coating were analysed by using several techniques including light microscopy, confocal laser scanning microscopy (CLSM) and electrochemical tests - electrochemical impedance spectroscopy (EIS) in 0.1M Na2SO4 solution (simulation of industrial atmosphere). The phosphate coating formation was evaluated after chosen exposure times from 15 minutes to 105 minutes in phosphating bath composed of MnO2, H3PO4 and demineralised H2O. The optimal exposure time of S355J2 steel in selected phosphate solution was determined from surface quality, corrosion resistance and energy consumption point of view.

All technical metals used not only in agriculture are subject to degradation processes, there are distinguished two main types: mechanical abrasion and physical-chemical degradation (corrosion). In order to lower abrasion of a machine part, it is necessary to use appropriate technical materials as well as an appropriate heat treatment. To minimize losses caused by corrosion, an appropriate anticorrosion system has to be used. This paper evaluates corrosion and mechanical resistance of waterborne acrylate anticorrosion systems sold on the Czech market. These paints were applied by an air flow technology. Mechanical characteristics of the applied coating were evaluated according to the ČSN EN ISO 4624 (pull-off test for adhesion), ČSN EN ISO 2409 (cross-cut test) and ČSN EN ISO 1520 (cupping test). As used anticorrosion systems were applied also on zinc-dipped coating, this duplex system was also subject to the mentioned tests. Corrosion resistance of the tested anticorrosion systems was analysed in the salt-spray environment (ČSN EN ISO 9227). Based on the results of the individual tests, there can be characterised adhesion, flexibility and mechanical resistance of waterborne anticorrosion systems as well as a further application on zinc layers. Corrosion tests analyse the process and visual appearance of corrosion attack.

The aim of the article was to check the internal defects in the butt welded joints by non-destructive TOFD (Time of Flight Diffraction) technique. Subsequently, the macrostructure from the defect indication site was evaluated and assigned to the TOFD ultrasound indication. Basic knowledge of ultrasonic TOFD testing are described in the theoretical part of a submitted paper. Ultrasound technique TOFD is non-destructive method that can detect internal defects inside test material without damaging it. It is a reliable method for detecting mainly flat internal defects such as incomplete root penetration, lack of fusion, etc. Ultrasonic test procedures and test results obtained in non-destructive testing of butt weld are shown in experimental part. Evaluation of the ultrasonic TOFD testing results, its advantages and disadvantages are described at the end of this article.

The Al-20Si-16Fe alloy (wt.%) was prepared by a combination of short-term mechanical alloying and consequential compaction via spark plasma sintering. The compaction was done at two different pressures of 80 MPa and 6 GPa to describe the influence of pressure onto a resulting properties of prepared alloy. The microstructure of both the prepared compact alloys showed presence of sub-micrometre particles embedded in the Al-matrix while some residual porosity was also observed. This corresponded to the lower compaction pressure of only 80 MPa, which, in comparison to the 6 GPa allowed to retain some porosity. The higher compaction pressure of 6 GPa resulted in a increase of the compressive strength of 1426 MPa while the hardness was slightly lower reaching still high 348 HV 5. On the other hand, the sample compacted by a pressure of 80 MPa reached compressive strength of 758 MPa while showing higher hardness of 411 HV 5. The difference in the observed properties can be attributed to a different compaction temperatures of 500°C (for 80 MPa) and of approximatelly 600°C (for 6 GPa).

The paper describes the research focused on the influence of the antimony as the modificator in the one of the most common aluminium foundry alloys - alloy AlSi7Mg0.3. The aim of described experiment was to examine the antimony addition influence on the AlSi7Mg0.3 alloy microstructure changes. The description of the changes was performed based on the analysis realized using confocal laser microscope and electron microscope complemented by energy dispersive spectrometry in microstructure induced by the addition of antimony. The changes in the alloy microstructure, which were evoked by the addition of antimony, caused the mechanical properties changes (especially ductility). This is the main purpose of the Al-Si alloy modification process. Mechanical properties of the alloy were analysed using static tensile test and the main parameter of the observed changes was the increase in ductility.

The article will be focused on monitoring the influence of the structure on the fatigue properties of aluminium alloys for the casting of type Al-Mg, especially EN AC 51200 and EN AC 51500. These alloys were selected on the basis of the chemical composition, where the content of most alloying elements is comparable, only in the case of the concentration of magnesium are these alloys significantly different. Fatigue properties of aluminium alloys were tested by three-point bending cyclic loading. The fracture surface of the testing sample was examined using scanning electron microscopy (SEM), where samples were observed on various stages of the fatigue process, their characteristics and differences of fracture surfaces.

Burnishing is a cold working process with superficial plastic deformation, which is to exert an external pressure through a very hard and smooth roller or ball on a surface to occur a uniform and work-hardened surface, to make it possible to reduce roughness, to increase the hardness and to produce residual stresses of compression. The unalloyed S 355 J0 steel specimens were machined on a conventional lathe to the proper dimensions; these machined specimens were then burnished by a simple locally designed and fabricated roller-burnishing tool. The main objective in this work is to determine a mathematical models statistically based on experimental design (response surface methodology) using central composite second-order rotatable design which allows to give the relationship between the two out parameters surface roughness and hardness, representative of the superficial layer surface caused by the four internal roller-burnishing parameters called: burnishing speed, force, feed and number of passes of the tool. The experimental results indicate that feed, burnishing force and speed are the most important and significant parameters to improve roughness surface, and feed, speed, burnishing force and number of passes are the most important and significant parameters to improve superficial hardness of S 355 J0 steel specimens. The surface roughness and hardness were improved from about 2.5μm to 0.15μm and from 176 HV to 226 HV respectively. The validated models with coefficient of determination R2 = 93.1% for surface roughness and R2 = 89.8% for hardness, seem correlate well with the experimental results.

In this paper, the results of an investigation done with face milling are presented. The changes in cutting force and surface roughness were studied through changing the values of depth of cut and the feed per tooth. Meanwhile the permanent value of the undeformed chip cross section, which was determined (fz and ap), remained permanent. Increasing fz and keeping the same value of Ac chip cross section, the ratio ap/fz changed in five grades from 0.5 to 8. It is shown, that if the feed is increased in the examined range so that the chip cross section is constant, then the value of the cutting force decreases, which decrease can be observed in all three force components. Accordingly, the mechanical power required for cutting is reduced. The results of the surface roughness investigations showed that initially a significant increase can be observed in the roughness with the gradual increase of the feed (up to ap/fz = 2.5), followed by a moderate increase afterwards.

This paper deals with the comparison of an analytical solution of the temperature field of a steam boiler pipe membrane wall using a numerical method calculation in the COSMOS/M programme. The result analysis showed that analytical calculating methods which are limited to 1D and 2D task types can be used for the approximate calculation of temperature in the selected locations of the membrane wall. With these methods it is not possible to obtain a complex view of the heat loading of the entire membrane wall or of the stress conditions caused by the thermal and pressure effect of steam-water mixture in the wall pipes. The results of numerical simulations have provided a complex image about the temperature and pressure distribution in the entire membrane wall of a steam boiler taking into account the material properties.

The current manufacturing production is characterised by increasing level of automation, emerging of the new light-weight and high-stiff materials that are technologically difficult to produce. These trends have significant impact on production productivity. The automation has brought significant reduction of non-productive time (fast workpiece and tool exchange, automatic control of product quality during technological process). In this situation, the machining time becomes the limiting factor. In present, the reducing of the machining time is possible to make only by either significant changes in conventional technologies or application of new technological principle. However, these secondary solutions in some production section are not sufficient because it requires a global solution. An example of un-equal time continuity in link production is fact that one pressing machine with the time per one piece in seconds can supply dozen of lathes with the time per one piece in minutes. The paper provides also the proposal to the productivity increase of critical technologies as turning and milling.

In this paper we analyze Weibull generated failures of equipment in discrete production. At first we will classify failures using ABC analysis. Obtained characteristics of each group of failures can be used to generate time of their occurrence and duration which are essential for assessment of their cost. We use optimization tool Solver from MS Office - Excel to solve problem of maintenance of machines. We optimize strategy of maintenance also according to cost of failures in categories ABC classification. Results of this optimization are tables, graphs, having that it can offer to managers a new unconventional access at the efficiency of investment. We create the proposed approach of solving models on demonstration example.

The phase analysis of the EN AW 6023 aluminum alloy after the heat treatment by short time aging was investigated. The good machinability of this heat treatable and lead free Al-Mg-Si wrought alloy is achieved by alloying of tin and bismuth. In experimental procedure, the solution annealing at 550 °C for 1 hour and subsequent water quenching of the analyzed alloy was realized. The short time artificial aging at 190 °C for 1 hour was carried out immediately after quenching. The microstructure analyses, the EDS analyses and the phase analyses using the hard X-ray diffraction by synchrotron radiation in DESY Hamburg were realized. Significant changes of the alloy phase composition were not observed after short time artificial aging applied on quenched and/or naturally aged alloy. Above all, the minority β''(Mg5Si6) phase was identified as a strengthening phase in alloy α(Al) solid solution as the majority alloy phase. In addition, the minority of Sn, Mg2Sn, Bi2Mg3, AlCu2Mn, Al15(Mn,Fe)3Si2 phases were identified in alloy microstructure.

Fracture surfaces of specimens broken by cyclic loading provide valuable information about individual stages of fatigue process. Changes in the loading conditions (character of fatigue loading, stress amplitude level, influence of cycle asymmetry ratio R, testing temperature, environment of test, etc.) and in the structure of tested material as well cause changes in the fatigue process, whose have effect on fracture surface resulting in change of fatigue properties. In this paper, authors describe the changes of fatigue process of nickel base superalloy Inconel 718 as a result of loading conditions change using SEM (Scanning Electron Microscopy) microfractography analysis of fractured surfaces. The various fatigue loading were, at the first, regular push-pull loading with asymmetry ratio R = -1 and frequency f = approx. 20 000 kHz (High Frequency and High Cycles fatigue Loading - HFL) and the second was three-point flexure loading with asymmetry ratio R = 0.116 / 0.507 and frequency f = approx. 150 Hz (Low Frequency and High Cycles fatigue Loading - LFL). All fatigue tests were done at room temperature.

Al-Zn-Mg-Cu alloys possess excellent mechanical properties, and therefore are used in aerospace and automotive industry. However, they are susceptible to localized corrosion such as pitting, intergranular and exfoliation corrosion, which is closely related to the precipitate size and distribution. Because the size and distribution of the precipitates are controlled by heat treatment, we investigated the influence of the heat treatment on corrosion behaviour and mechanical properties of the AA 7075 alloy. Audi test, internal Audi standard PV 11 13 for automotive industry, was chosen to evaluate the corrosion behaviour of the as-cast, T5 and T6 heat treated aluminium alloy 7075. Mechanical properties were studied through the tensile test and hardness measurements. The highest corrosion rate and the depth of corrosion attack penetration were observed for the T5 state, while the T6 state evinced the best resistance to localized corrosion and the highest mechanical properties.

In this work, kinetics of the intermediary phase formation in Ti-Al system during reactive sintering at 800 °C was investigated. Because it is very difficult to determine the kinetics on the powder mixture, special model system was utilized. This model consisted of solid titanium and molten aluminium and the intermediary phase formation was observed on the interface solid - liquid state at various times. Only TiAl3 phase formed during the test. The thickness of the layer was changing and based on these results it can be estimated how the process is controlled. It was revealed that the formation of TiAl3 phase is controlled by the rate of chemical reaction and the incubation period is 5 and 75 min.

This work deals with optimization of Spark Plasma Sintering conditions for the preparation of Ti-Al-Si alloys. Ti-Al-Si alloys are appropriate material for high-temperature applications, especially for aerospace and automotive industry. They are characterized by low density, good mechanical properties and resistance against oxidation. Ti-Al-Si alloys were prepared by powder metallurgy using reactive sintering, followed by milling and Spark Plasma Sintering. Preparation of intermetallic compounds is complicated due to high melting points of intermediate phases, the exothermic reaction during their formation and high reactivity of the melt with melting crucible. TiAl10Si20 alloy was prepared by Spark Plasma Sintering under a pressure of 48 MPa and by High Pressure Spark Plasma Sintering under pressure of 6 GPa. The temperature was chosen between 1100 °C and 1204 °C. The porosity of TiAl10Si20 alloy decreases with pressure and with the high pressure also increases the hardness by 200 HV 5. Abrasive wear resistance of TiAl10Si20 alloy is very good.

Under isothermal treatment conditions, bainite transformation involves decomposition of austenite into a nonequilibrium structure consisting of needles of super-saturated bainitic ferrite and carbide precipitates. Similarly to martensitic transformation, bainitic ferrite forms by shear mechanism. Owing to relatively low temperature, only interstitial elements, predominantly carbon, can migrate by diffusion. Depending on the transformation temperature, carbon migrates from ferrite and forms carbides, either within bainitic ferrite needles and at the interphase interface between bainitic ferrite and austenite, or only within bainitic ferrite needles. In conventional steels, bainite transformation continues until the decomposition of austenite phase is almost complete. If the steel contains enough silicon, carbide precipitation may be suppressed or even prevented altogether. In such case, carbon which diffuses from the needles of bainitic ferrite may enrich adjacent austenite areas. Depending on heat treatment conditions, the carbon-enriched austenite may become sufficiently stable to resist decomposition and remain in the microstructure.

Ride of vehicles along curved track is a serious technical problem, which for the long term requires attention of vehicle engineers as well as track designers. It is especially interesting to observe behavior of tram cars passing a curved track, because they should be able to pass arcs up to 17 meter radius. Ride of a vehicle along such strongly curved track is nowadays accompanied by significant wear in rail-wheel contact, increased bogie and track stress and by generation of noise. One of the key causes of this unfavorable phenomenon is an increase of slip velocities in rail-wheel contact. This paper is based on simulation analysis, which compares different ways of minimizing slip velocities and thus mitigating the impacts of passing vehicles on the track as well as on the car itself. Bogies with and without wheelset steer possibility were analyzed. Both bogies were also analyzed with wheel profiles of different delta R function course.

While down-scaling of micro milling process is similar to the conventional process, there are specific issues that differ from macro machining due to higher ratios of feed per tooth to tool radius and tool run-out to tool diameter, size-effect, minimum chip thickness, elastic-plastic deformation, microstructure effects, etc. One of the challenges in micro machining is attaining accurate and reliable machining parameters, which can reduce tool wear and breakage to achieve higher productivity and quality at a lower cost. Therefore, this paper presents a new mechanistic model for predicting the precise process parameters considering material properties and principles of micro-milling under various cutting conditions. The proposed model also takes into account the nonlinearity and dynamics of minimum chip-thickness, micro-milling cutting forces considering cutting, as well as edge and damping coefficients into. The predicted stability lobes and the stability limits from experiments are in sufficient agreement. The research of micro-scale milling parameters is significant to improve the precision of machined parts, reduce the wear and tear of the micro-milling blade and extend the life of micro-tools.