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On the evaluation of cutting performance when machining
Kolomý, Štěpán ; Fiala, Zdeněk (referee) ; Píška, Miroslav (advisor)
This bachelor thesis focuses on cutting performace during intterupted cutting conditions and on the problems of intermittent turning. There is tested cutting performace of indexable inserts from cubic boron nitride and ceramic during interrupted face turning in experimental part. Tools wear and shape of chips are analyzed. The output of this work is data processing and their comparison.
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Testing of cutting parameters for UMCo50 machining
Jakubec, Thomas ; Kolomý, Štěpán (referee) ; Zemčík, Oskar (advisor)
The diploma thesis deals with the machinability of materials, the theoretical part describes the factors that have a dominant influence on machinability. The basic aspects according to which the machinability of the material and the wear of the tool are determined are also given here. The distribution of cobalt alloys is given here, including the UMCo-50 alloy, which is the subject of experimental research. It is an alloy for high-temperature use with good abrasion resistance and is used especially where other materials lose their mechanical properties due to the high temperature. The practical part followed the thesis of my colleague Ing. Peter Prno [1], which due to lack of time could not measure all the necessary quantities, resp. course of back wear for the remaining two cutting speeds. During the experiment, the wear of the tool back was monitored as a function of time at different cutting speeds in turning technology. The main goal was to determine the resulting tool life at the remaining cutting speeds and thus obtain a more accurate Taylor dependence. The turning forces, the quality of the machined surface and the formation of chips were also monitored during turning.
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Testing of high-temperature corrosion resistance of 16M03 steel
Šikl, František ; Kolomý, Štěpán (referee) ; Zemčík, Oskar (advisor)
The aim of this work is to design and perform an experiment that simulates the environment of a municipal waste incinerator. However, the whole process of corrosion in real life can take several years, so it is necessary to accelerate these processes in both higher areas and more aggressive environments. The investigated material is 16Mo3 steel. The first part of the work is a search of selected issues of corrosion and materials used in the energy industry. The next part of the work deals with the design of the experiment, which consists of several parts. These may include the appropriate choice of chemical compounds used or the choice of measured temperatures or sample preparation, the experiment being adapted to the available equipment of the BUT FSI workshop. In the last part of the work, testing of the specified material for temperatures of 900 °C, 975 °C and 1 050 °C is performed, while the composition of the mixture is designed as 35 wt. % Na2SO4, 30 wt. % KCl at 35 wt. % NaCl. The measured values are compared depending on the temperature, where, as predicted, a larger graphical dependence can be seen at higher values. At the end, the results of corrosion loss of 16Mo3 steel were compared with Inconel 625 superalloy, where the theory already differs from practice. Furthermore, chemical analyzes from the experiment were performed at 1 050 °C and, based on these obtained values, the proportion of individual elements can be adjusted with the salt mixture used. This adjustment is recommended to reduce the NaCl content due to the higher Na content, as well as to increase the KCl content due to the low K content.
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Optimization of the production process of a precision machined part
Kolomý, Štěpán ; Sedlák, Josef (referee) ; Píška, Miroslav (advisor)
This master‘s thesis deals with optimization of cutting conditions when machining of precise parts in mass production. In experimental part of this thesis is a comparison of the roughing tool with indexable cutting inserts with the new implemented milling cutter. Tool wear of both roughing tools has been analysed. The surface roughness analysis after machining with the face milling cutter was performed. The output of this work is to obtain optimal cutting conditions to gain a minimum surface roughness.
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Machinability testing of the UmCo50 alloy
Chladil, Jan ; Kolomý, Štěpán (referee) ; Zemčík, Oskar (advisor)
The diploma thesis deals with the problem of machining of refractory and corrosion resistant alloys with a focus on the superalloy UMCo-50. The thesis discusses the properties of suitable cutting materials for turning superalloys, with emphasis on coated sintered carbides, which form the most numerous group of cutting materials. The basic factors that directly affect not only the durability of the cutting edge but also the machinability of the materials are described, together with the manifestations of cutting edge wear. Subsequently, using the theoretical knowledge, an experiment is designed to qualify the machinability of the mentioned superalloy, while maintaining compatibility with the tests already carried out.
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Design of a dynamometer holder for a turning center
Vystrčil, Ondřej ; Zemčík, Oskar (referee) ; Kolomý, Štěpán (advisor)
This thesis summarizes the possibilities of measuring the load on cutting during turning, the operational principle, and the requirements for operating the Kistler 9257B dynamometer. Within this study, several conceptual designs of the dynamometer holder for the SP 280 SY CNC turning centre were proposed. The best design was selected based on spatial considerations and collisions with the machine. The construction of individual components of the selected holder design was resolved. Necessary calculations and simulations for the safe operation of the holder were also performed. Based on the 3D model, CNC machine programs were created for machining the individual parts. Subsequently, the designed holder was manufactured and tested in the device. No deviations were found during the tests compared to the normal operation of the machine without the dynamometer holder.
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Machining of thin-walled components on a CNC lathe
Veselský, Radim ; Kolomý, Štěpán (referee) ; Slaný, Martin (advisor)
This work was focused on the design and production of a clamping device for clamping thin-walled circular workpieces on a CNC machine. Cutting forces were measured using a dynamometer. From these forces the highest power was derived. The minimum clamping force for clamping the workpiece was calculated. Using simulation, the most suitable angle of spacing of the clamping surfaces was determined. Based on this finding, the jaws were designed and manufactured. 5 samples were processed. Three samples were machined in the original jaws, two samples were machined in newly manufactured jaws. Each jaw was clamped with two specified clamping pressures. The machined samples were scanned with an optical scanner and measured in a measuring program. A clamping simulation took place with the determined pressures of both jaws in the simulation program. Conclusions were drawn from the calculations and the verification experiment.
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Evaluation of machinability of a 3D printed material
Krestová, Alžběta ; Chladil, Josef (referee) ; Kolomý, Štěpán (advisor)
The aim of the bachelor thesis was to evaluate the machinability of 3D printed material by Bound Metal Deposition method under different conditions during milling. The forces during machining were measured and the surface roughness and the resulting wear on the tool were also investigated. The values were recorded and further evaluated, where the results were compared and recommendations were made as to the conditions under which low values of wear are produced. The result was that lower wear values are achieved when machining without cooling and at low cutting speed and feed rate.
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Testing of high-temperature corrosion resistance of 16M03 steel
Šikl, František ; Kolomý, Štěpán (referee) ; Zemčík, Oskar (advisor)
The aim of this work is to design and perform an experiment that simulates the environment of a municipal waste incinerator. However, the whole process of corrosion in real life can take several years, so it is necessary to accelerate these processes in both higher areas and more aggressive environments. The investigated material is 16Mo3 steel. The first part of the work is a search of selected issues of corrosion and materials used in the energy industry. The next part of the work deals with the design of the experiment, which consists of several parts. These may include the appropriate choice of chemical compounds used or the choice of measured temperatures or sample preparation, the experiment being adapted to the available equipment of the BUT FSI workshop. In the last part of the work, testing of the specified material for temperatures of 900 °C, 975 °C and 1 050 °C is performed, while the composition of the mixture is designed as 35 wt. % Na2SO4, 30 wt. % KCl at 35 wt. % NaCl. The measured values are compared depending on the temperature, where, as predicted, a larger graphical dependence can be seen at higher values. At the end, the results of corrosion loss of 16Mo3 steel were compared with Inconel 625 superalloy, where the theory already differs from practice. Furthermore, chemical analyzes from the experiment were performed at 1 050 °C and, based on these obtained values, the proportion of individual elements can be adjusted with the salt mixture used. This adjustment is recommended to reduce the NaCl content due to the higher Na content, as well as to increase the KCl content due to the low K content.
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Testing of cutting parameters for UMCo50 machining
Jakubec, Thomas ; Kolomý, Štěpán (referee) ; Zemčík, Oskar (advisor)
The diploma thesis deals with the machinability of materials, the theoretical part describes the factors that have a dominant influence on machinability. The basic aspects according to which the machinability of the material and the wear of the tool are determined are also given here. The distribution of cobalt alloys is given here, including the UMCo-50 alloy, which is the subject of experimental research. It is an alloy for high-temperature use with good abrasion resistance and is used especially where other materials lose their mechanical properties due to the high temperature. The practical part followed the thesis of my colleague Ing. Peter Prno [1], which due to lack of time could not measure all the necessary quantities, resp. course of back wear for the remaining two cutting speeds. During the experiment, the wear of the tool back was monitored as a function of time at different cutting speeds in turning technology. The main goal was to determine the resulting tool life at the remaining cutting speeds and thus obtain a more accurate Taylor dependence. The turning forces, the quality of the machined surface and the formation of chips were also monitored during turning.
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