Manufacturing Technology Journal, 2019 (vol. 19), issue 1
Tribological Properties of Brass Surfaces Machined by Abrasive - Free Ultrasonic Finishing Process
Zdeněk Aleš, Jindřich Pavlů, Monika Hromasová, Jaroslava Svobodová
Manufacturing Technology 2019, 19(1):3-8 | DOI: 10.21062/ujep/235.2019/a/1213-2489/MT/19/1/3 
Brass mechanical properties are not ideal, particularly when the brass is exposed to the effects of mechanical wear. Final finishing of functional surface of machine component is substantial for the particular choice of brass. The aim of the research was to approve or disapprove the hypothesis if abrasive - free ultrasonic finishing (bufo) of brass has higher wear resistance of surface compared to the classical machining. The results of the experiment showed that abrasive - free ultrasonic finishing (bufo) has a major impact on the size of the elliptical wear area. Surface finishing by classic machining formed on average a 41% larger elliptical wear...
Degradation of a Grinding Wheel when Grinding Cermet Materials and Its Influence on the Grinding Process
Tomas Baksa, Pavel Adamek, Ondrej Hronek, Miroslav Zetek
Manufacturing Technology 2019, 19(1):9-13 | DOI: 10.21062/ujep/236.2019/a/1213-2489/MT/19/1/9
This article deals with the experimental grinding of cermet materials. Two types of cermet materials from different suppliers were ground under constant grinding conditions using a diamond grinding wheel. The main aim was to determine the influence of the grinding on the degradation of the grinding wheel and changes in the grinding process. Both types of cermet were ground with the same strategy and the same number of passes. The grinding wheel was analysed during grinding using an optical scanning device to observe the changes on the grinding wheel surface. Clogging and wear of the grinding wheel occurred on the surface as the amount of material removed...
Applicability of Microcellular Injection Molding Process
Pavel Brdlík, Vojtěch Rajnoha
Manufacturing Technology 2019, 19(1):14-17 | DOI: 10.21062/ujep/237.2019/a/1213-2489/MT/19/1/14
Microcellular injection molding is relatively new and progressive technology for production of lightweight constructions. The weight reduction, elimination of sink marks, internal stresses and deformation of products are the main advantages of this unconventional technology. On the other hand, decrease in mechanical properties and poor surface quality are the application restrictions. There are several aspects affecting formation of microcellular structure and final properties of injection molded products. As a one of the most important aspects there is used material. Therefore, the main goal of this article was investigation the influence of different...
Determination of Transformation Temperatures of Advanced High-Strength Steels and Their Use in Designing Q&P Process Routes
Dagmar Bublíková, Hana Jirková, Mária Behúlová, Josef Krajčovič
Manufacturing Technology 2019, 19(1):18-22 | DOI: 10.21062/ujep/238.2019/a/1213-2489/MT/19/1/18
Determining transformation temperatures of novel steels is an important step towards finding parameters for their heat treatment. In advanced high-strength steels for Q&P processing (Quenching and Partitioning), the crucial processing characteristics are the temperatures of the start and end of austenitization and the Ms temperature. Q&P processing is characterized by quenching from a full-austenitization temperature to below the Ms, and subsequent holding at the partitioning temperature. This leads to martensitic microstructures with retained austenite between martensite needles and to ultimate strengths above 2000 MPa and elongation levels...
The Influence of a Ceramic Recoater Blade on 3D Printing using Direct Metal Laser Sintering
Milan Daňa, Ivana Zetková, Pavel Hanzl
Manufacturing Technology 2019, 19(1):23-28 | DOI: 10.21062/ujep/239.2019/a/1213-2489/MT/19/1/23
This paper deals with 3D printing of metal parts. There are many principles of 3D printing, for example, DMLS, SLS, CLADDING, etc. This paper is limited to 3D printing using DMLS (Direct Metal Laser Sintering). 3D printing using DMLS can create complex geometries that cannot be created using other metal manufacturing processes. This principle is based on sintering of metal powder in thin layers. Thin layers of powder are applied by a recoater blade. The shape of the part is sintered with a precise and high-wattage laser in this layer. The part is built layer by layer. The printer used for the experimental part of this paper was an EOS M290. The material...
Corrosion of 3D-Printed AlSi9Cu3Fe Alloy
Michaela Fousova, Veronika Valesova, Dalibor Vojtech
Manufacturing Technology 2019, 19(1):29-36 | DOI: 10.21062/ujep/240.2019/a/1213-2489/MT/19/1/29
Although 3D printing offers many advantages over casting, it can alter the corrosion behaviour of processed metals and alloys. The corrosion behaviour is related primarily to the microstructure, which is very fine and heterogeneous in 3D printed metals due to very high cooling rates and the additive way of manufacture layer by layer. Therefore, we carried out corrosion tests according to the Audi internal standard to demonstrate how the 3D printing process influenced the corrosion behaviour of the AlSi9Cu3Fe alloy prepared by selective laser melting compared to a conventional casting. Corrosion rates were determined from mass losses and corrosion attacks...
Structural Changes and Microstructure of Maraging Steel Lattice Structures using Additive Manufacturing
Pavel Hanzl, Ivana Zetková, Ludmila Kučerová
Manufacturing Technology 2019, 19(1):37-41 | DOI: 10.21062/ujep/241.2019/a/1213-2489/MT/19/1/37
Direct Metal Laser Sintering (DMLS) is a method of additive manufacturing (AM), which builds metal parts in a layer by layer procedure based on a CAD template. The melting of metal powder by an energy beam and successful mastering of the whole manufacturing procedure requires complex management. Physical and chemical metallurgical phenomena occur during melting of the material and the final microstructure depends on many factors. This study investigates the microstructure of struts depending on their distance from the building platform. It is known that metal powder does not allow the dissipation of heat in the same way as molten material due to gas...
Concept Design of a Tram Bogie with Atypical Suspension
Vladimír Hauser, Kateryna Kravchenko, Mária Loulová, Olena Nozhenko, Jozef Harušinec, Alfréd Pavlík, Oleksij Fomin
Manufacturing Technology 2019, 19(1):42-48 | DOI: 10.21062/ujep/242.2019/a/1213-2489/MT/19/1/42
In the urban railways environment, there is considerable stress of the track due to operation, which results in extensive deformation of the track geometric position, wear of the rail heads, expansion of the free channel of the track, leading to an increase in steering forces in the rail-wheel contact and further worsening of the situation. The authors perceive this situation primarily as a consequence of an inappropriate bogie concept of the operating vehicles - not of the track quality. The article focuses on designing a new bogie concept that takes into account the specific environmental conditions for which it is intended. The presented bogie design...
Influence of Manufacture Process Parameters on Dimensional Stability of Small Blade Castings
Aleš Herman, Irena Kubelková, Ondřej Vrátný, Bohumír Bednář
Manufacturing Technology 2019, 19(1):49-53 | DOI: 10.21062/ujep/243.2019/a/1213-2489/MT/19/1/49
The production of precise castings by investment casting becomes an increasingly important manufacturing technology and many of isues of this method have to be addressed. This paper deals with evaluation of critical points on wax patterns of small blades. After the casting of certain product, the casting had a deviation from the required dimension. Investigation revealed that the effect on the resulting dimensional deviation is not only the casting process but also the wax pattern injection process itself. The engine and turbine blades are one of the most important parts in turbine or aircraft engine machinery. Casting deformation is an important feature...
The Manganese Influence on the AlSi12 Alloy Alfinal Bath Mechanical Properties Change
Lubomír Hodinář, Jaroslava Svobodová, Iryna Hren, Jaromír Cais, Štefan Michna
Manufacturing Technology 2019, 19(1):54-63 | DOI: 10.21062/ujep/244.2019/a/1213-2489/MT/19/1/54
The experiment described in this article deals with the possibility of AlSi12 alloy alfinal bath mechanical properties change used in the manufacture of the compression ignition engines pistons by the addition of manganese. The alfinal bath is intended for the aluminium layer deposition which provides more convenient connection of the carrier with the aluminum alloy after casting in the mold. The analysis performed in the experiment were focused on the assessment of the manganese addition influence in the form of the AlMn20 master alloy on the resulting mechanical properties of the AlSi12 alloy in which the iron content gradually changes (up to 7 wt....
Analysis of the Influence of Fuel on Oil Charge and Engine Wear
Michal Holubek, Martin Pexa, Jindrich Pavlu, Jakub Cedík, Katerina Vesela, Peter Kuchar
Manufacturing Technology 2019, 19(1):64-70 | DOI: 10.21062/ujep/245.2019/a/1213-2489/MT/19/1/64
The combustion engine is a very widespread energy source for many machines and devices. Diesel, gasoline, LPG, CNG, as well as many biofuels such as ethanol, butanol, etc. are used as propellants at the present time. During the running of the internal combustion engine, some fuels penetrate into the crankcase and degrade the engine oil. This potentially reduces the lubricating ability of the oil and changes its degradation process. Submitted paper follows possible changes in lubricating capabilities of oil used in engines with specific fuels: n-butanol, LPG and diesel. Different type of fuel used in combination with an inappropriate operating mode...
Non-destructive Evaluation of Pore Size and Structural Change in Geopolymer Composite Materials with Added Fibres
Marcela Kolínová, Totka Bakalova, Lukáš Voleský, Pavel Kejzlar, Vladimir Kovačíč
Manufacturing Technology 2019, 19(1):71-76 | DOI: 10.21062/ujep/246.2019/a/1213-2489/MT/19/1/71
This paper introduces a non-destructive method of analysis of the internal structure, occurrence and pore size in a specific volume of geopolymer composite material, with and without the addition of inorganic fibres in the form of meshes using computed tomography. A desktop micro-tomography device Skyscan 1272 was used for visualization and accurate analysis of the interlacing points in the basalt and carbon fibre meshes and for evaluating the adhesion of the fibres to the matrix of the composite material. An appropriate resolution was selected both for displaying the interlacing points in the inorganic fibres and for visualization and analysis of...
Influence of Heat Treatment on the Change of Al-Si Coating Properties at Ultra-high Strength Sheets
Michaela Kolnerova, Jiří Sobotka, David Koreček, Pavel Solfronk
Manufacturing Technology 2019, 19(1):77-81 | DOI: 10.21062/ujep/247.2019/a/1213-2489/MT/19/1/77
Paper deals with the evaluation of protective coating surface layer Al-Si at boron steel 22MnB5. Parts from these steels are used at the car-body design. Such parts are produced by hot forming technology that means not only higher requirements on material but also on the surface layer. Coatings are used to protect surface against oxidation during heating and also support the own forming process inside the tools. In this paper is evaluated the protective layer change during heat treatment - heating in furnace (8, 12 and 16 min). Performed microscopic analysis of Al-Si surface layer proves the thermal regime influence on the change of coating properties.
Determination the Influence of Load-rate on Strain and Spring-back Magnitude for Titanium Alloy by means of Numerical Simulation
David Koreček, Pavel Solfronk, Jiří Sobotka, Michaela Kolnerová
Manufacturing Technology 2019, 19(1):82-88 | DOI: 10.21062/ujep/248.2019/a/1213-2489/MT/19/1/82
Nowadays, when there is strong tendency to still accelerate production process and thus save time and money, is very necessary to take into account influences of the individual process parameters on forming process. Another tendency tries to reduce weight of parts at keeping the required mechanical properties. These aspects lead also to utilization numerical simulations for modelling processes and materials with the specific utility properties. This paper deals with the influence of load-rate (thus also strain-rate) on the own process of metal sheet forming (namely U-die bending) - in light of both achieved deformation and subsequent spring-back of...
Microstructure of the Mg-4Y-3RE-Zr (WE43) Magnesium Alloy Produced by 3D Printing
Patrícia Krištofová, Jiří Kubásek, Dalibor Vojtěch, David Paloušek, Jan Suchý
Manufacturing Technology 2019, 19(1):89-94 | DOI: 10.21062/ujep/249.2019/a/1213-2489/MT/19/1/89
In this study, the three microstructure of the as-cast, hot-extruded, and 3D printed Mg-4Y-3RE-Zr (WE43) magnesium alloy was studied. The selective laser melting (SLM) process was used for 3D printing. The study was aimed at mapping the microstructure of a 3D printed magnesium alloy produced by the SLM process. Magnesium alloys made in the form of 3D printing are relatively new production processes. The study therefore this process compared with current processes, which are now well known and mapped. It was therefore studied the microstructure produced by three different processes of production. The microstructure and chemical composition of present...
Thermo-mechanical Treatment of 0.4C-0.6Mn-2Si Steel with Various Soaking and Annealing Hold Temperatures
Ludmila Kučerová, Martin Bystrianský, Štěpán Jeníček
Manufacturing Technology 2019, 19(1):95-100 | DOI: 10.21062/ujep/250.2019/a/1213-2489/MT/19/1/95
Middle carbon low alloyed steel 0.4C-0.6Mn-2Si was subjected to thermo-mechanical treatment typical for TRIP (transformation induced plasticity steels). The processing consisted from soaking at the temperatures of 850-1000 °C and cooling at 30 °C/s to various annealing holds in bainite transformation temperature interval of 350-500 °C. During the cooling from the soaking temperature, two compressive deformations were carried out, the second one always at 720 °C. Resulting microstructures were analysed using light and scanning electron microscopy. X-ray diffraction phase analysis was carried out to establish volume fraction of retained austenite and...
The Influence of the Gate Geometry on Selected Process Parameters in the High Pressure Die Casting Technology
Jan Majernik, Stefan Gaspar, Martin Podaril, Jan Kolinsky
Manufacturing Technology 2019, 19(1):101-106 | DOI: 10.21062/ujep/251.2019/a/1213-2489/MT/19/1/101
The design of the gating system and the adjustment of the technological parameters of high pressure die casting are closely correlated. Correct connection of the gating system structure and technological parameters will be reflected in the final casting quality. Significant influence on the filling progress of a mold cavity has a gate and its geometry. Within the gate, the final increasing of melt flow velocity arises and determines the filling mode. The contribution is devoted to the influence of the gate height on selected technological parameters. The obtained data are being evaluated and on the basis of the experimental results assessment, the...
The Research of the Effect of High Fe Content on AlSi9NiCuMg0.5 Alloy
Štefan Michna, Iryna Hren, Jaroslava Svobodová
Manufacturing Technology 2019, 19(1):107-113 | DOI: 10.21062/ujep/252.2019/a/1213-2489/MT/19/1/107
The aim of the research on the newly developed eutectic silumin type AlSi9NiCuMg0.5, developed and patented by a team of staff of the Faculty of Mechanical Engineering, was to determine the cause of the cracking of castings under operating conditions. When the technology was put into practice, the casting was cast and then used to break the entire casting section and create a crack that crosses the whole cross section. Castings were cast by low-pressure die casting technology, where the mold is fed into the mold cavity via a cast iron tube. The essence of the research was to perform a fractographic analysis of the fracture area, to identify the structure...
Optimization of Production Flow through the CRAFT Method
Radek Modrovský
Manufacturing Technology 2019, 19(1):114-117 | DOI: 10.21062/ujep/253.2019/a/1213-2489/MT/19/1/114
The article describes usage of the CRAFT method and its influence on the optimization of flow logistics. The method helps to reduce the cost of basic material flow determination in production, assembly of production units, material handling, storage of individual parts and the transport of finished products. By using the method, long traffic routes, unproductive times and warehouse inventory that unnecessarily increase our costs were removed. In today's competitive environment, it is necessary to improve continuously all processes not only in production, and this method enables us to effectively achieve defined business goals.
Theoretical Calculations of the Foaming Properties of Powder Agents for the Production of Aluminium Foams
Iva Nová, Karel Fraňa, Jiří Machuta, Iva Nováková
Manufacturing Technology 2019, 19(1):118-122 | DOI: 10.21062/ujep/254.2019/a/1213-2489/MT/19/1/118
This paper presents the theoretical calculations of the foaming process of selected powder foaming agents (TiH2, CaH2, MgH2, ZrH2, CaCO3 and MgCO3) regarding the volume of gas, relative density and density of the metal foam obtained with respect to the use of a certain amount of powdered blowing agent. This work is carried out in the frame of the university project in which a small subproject is dealing with the problem of the cellular lightweight metal structures. Furthermore by calculating the diffusion of hydrogen in both solid and liquid aluminium there were found results for the duration of the anticipated action of the powdered blowing agent...
The Thermal Energy Influence on the Surface Layer of Construction Steels during Laser Beam Cutting
Martin Ovsik, Michal Stanek, Lenka Hylova, Miroslav Manas, Pavel Stoklasek
Manufacturing Technology 2019, 19(1):123-128 | DOI: 10.21062/ujep/255.2019/a/1213-2489/MT/19/1/123
The presented article deals with the thermal energy influence on various types of construction steels during laser beam cutting. When the material is cut by a laser, the workpiece is subjected to intensive thermal load. Due to this influence, steels hardness is increased and the structure is changed.The aim of this study is to verify how the thermal energy influences the surface layer of material during laser cutting. The influence was studied on data measured by DSI (depth sensing indentation) micro-hardness method. Each sample was subjected to cross-section from edge to the distance of 20 mm from the edge measurement. To evaluate surface layers...
Effect of Cryogenic Treatment on Properties of Cemented Carbides
Vojtěch Průcha, David Bricín, Antonín Kříž
Manufacturing Technology 2019, 19(1):129-134 | DOI: 10.21062/ujep/256.2019/a/1213-2489/MT/19/1/129
The main goal of this paper is to present experiments exploring the effect of cryogenic treatment on the properties of cemented carbides. The experimental materials were chosen from three basic groups of cemented carbides with different binders and different WC grain sizes. One half of the specimens were cryogenically-treated, whereas the other half were in the as-received condition. The specimens were ground and polished using metallographic procedures. Effects of cryogenic treatment were studied by metallographic observation using light and scanning electron microscopes, by X-ray analysis of phase composition and by measuring Vickers hardness and...
Advantages of Additive Technologies Usage in Design of Cooling Channels
Karel Raz
Manufacturing Technology 2019, 19(1):135-138 | DOI: 10.21062/ujep/257.2019/a/1213-2489/MT/19/1/135
Main aim of this paper is to analyze the thermal behavior of different cooling channels and to describe advantages of manufacturing of a mold with these channels using a 3D printer instead of drilling machines. This work was primarily done by the usage of virtual simulation. Validation of thermal simulations was performed by usage of simple analytical solution. A simple model of molded brick was designed to analyze the cooling time and the temperature distribution in the mold when changing the cross section of the cooling channels. Three types of different rectangular cross-sections and one circular were chosen. All of them have the same area. The...
Effect of Heating Rate on the Phases Formation in Ti-20 wt. % Al Powder Mixture
Andrea Školáková, Pavel Salvetr, Pavel Novák
Manufacturing Technology 2019, 19(1):139-143 | DOI: 10.21062/ujep/258.2019/a/1213-2489/MT/19/1/139
In this work, the effect of heating rate on the reaction temperatures in Ti-20 wt. % Al powder mixture subjected to reactive sintering process were studied and microstructure, phase composition and porosity of the reaction products were described. This system was studied because the alloys based on Ti-Al intermetallics are modern high-temperature materials and their production by common metallurgical routes is problematic. Reactive sintering could potentially replace currently used method - melt metallurgy. However, many phases form during this process and some of them are undesired. For this reason, it is necessary to describe the temperatures and...
Input Data Acquisition Possibilities for Numerical Simulation of Drawing Process by means of the Contact-less Optical System and Thermo-camera
Jiri Sobotka, Pavel Solfronk, Michaela Kolnerova, David Korecek
Manufacturing Technology 2019, 19(1):144-149 | DOI: 10.21062/ujep/259.2019/a/1213-2489/MT/19/1/144
Drawing process is generally influenced by many technological parameters (e.g. holding pressure, friction coefficient, etc.) and all of them should be considered for numerical simulation of such process. This paper deals with the possibilities how to determine one of the parameters that is quite difficult to be taken into account - magnitude of heat generated during forming process. In this case only heat generated by plastic deformation was determined, thus static tensile test at different loading rates was performed. Contact-less optical system ARAMIS and Thermo-camera FLIR SC660 was used to measure distribution of both plastic deformation and temperature...
Ionized Air as a Process Medium for Machining
Karol Vasilko, Rudolf Matija
Manufacturing Technology 2019, 19(1):150-155 | DOI: 10.21062/ujep/260.2019/a/1213-2489/MT/19/1/150
The application of cutting liquids in the machining of the pertsgreatly affects the working environment. Descpite the efforts to prolong life, chemical aliminaion of bacteria formation, development of new liquid configurations, their negative influence on production (health hazard to the operator, corrosion of workpieces, need of recycling or disposal), it outweighs the benefits (decrease of cutting forces, cutting temperature reduction).The good is a gaseous environment. The current gaseous environments show the current application of ionized air. In the article are experimental results when applying this media during machining.
A Study of Factors Influencing Sound Absorption Properties of Porous Materials
Martin Vašina, Lumír Hružík, Adam Bureček, Miroslav Mahdal, Katarína Monková, Peter Pavol Monka
Manufacturing Technology 2019, 19(1):156-160 | DOI: 10.21062/ujep/261.2019/a/1213-2489/MT/19/1/156
A big accent is put on environmental protection at the present time. Noise belongs in general to negative factors of our environment. For this reason, it is necessary to perform suitable measures in order to eliminate noise. For example, it is possible to apply sound absorbers in order to damp noise. Materials with porous, spongy and fibrous structure belong generally to suitable materials in terms of noise damping. The aim of the paper is to investigate sound absorption properties of different types of porous materials. Frequency dependencies of the sound absorption coefficient over a frequency range of 150-6400 Hz were determined by the transfer...
Destructive and Non-destructive Assessment of the Thickness of Oxide Layers of Super-heater Tubes
Jana Veselá, Pavel Mares, Petra Bublikova
Manufacturing Technology 2019, 19(1):161-167 | DOI: 10.21062/ujep/262.2019/a/1213-2489/MT/19/1/161
Tubes of super-heaters and heaters used in conventional power plants are exposed to coolant and high temperatures. The growing oxide layer on the inner surface reacts over time as a heat insulator on the water side and reduces heat transfer through the wall of the tube. A relatively thin oxide layer already contributes to the boiler efficiency and causes a permanent overheating of the tube wall. As a result of overheating at the site, the intercrystalline cracks leading to the bursting of the tube are developing. The secondary problem of the growth of oxide layer thickness is so-called exfoliation. For non-destructive evaluation of the thickness of...
Characteristic Signal of FT3 Measuring Probe
Jiri Vit, Martin Novak
Manufacturing Technology 2019, 19(1):168-171 | DOI: 10.21062/ujep/263.2019/a/1213-2489/MT/19/1/168
The article deals with the determining of the characteristic signal of the inductive FT3 measuring probe, that is used on the roundness machines of Jenoptik IM producer. The research was the basis for generalized recommendations for the calibration of the probe, which was published in the article "A roundness machine measuring probe calibration". The signals of eight FT3 probes have been acquired and evaluated for repeatability and mutual equality. Five signals of each individual probe were taken immediately for repeatability evaluation. The deviations of the individual signals from the mean signal and the deviations of the signal first derivative...
Electromagnetic Analysis of the Updated Fast Control Coil for EAST
Xianewei Wang, Zhaoliang Wang, Fei Xie, Qing He, Xiulian Li, Wentao Xie
Manufacturing Technology 2019, 19(1):172-176 | DOI: 10.21062/ujep/264.2019/a/1213-2489/MT/19/1/172
Fast control coil is one of the most important components for EAST device to control the vertical stability of plasma. However, once the heating power of EAST is updated to 36 MW, fast control coil doesn't adapt to the new operation state and couldn't provide effective control for plasma vertical instability. Thus, insulation material with ITER-like magnesium oxide is developed to withstand high radiation and the coil position is also relocated to obtain more effective instability control. Given the relocation of fast control coil, electromagnetic load acting on coil-self and feeders are calculated based on elliptical integral and Ampere force law....