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The use of surface modifications in recent technical practice
Červinka, Martin ; Čelko, Ladislav (referee) ; Klakurková, Lenka (advisor)
Bachelor's thesis deals with problems of surface treatment materials and their basic division. Work is detail focused on technology of thermal spray coatings. This work summarizes the basic information about the technology thermal spray coatings, their features and an overview of methods for their production. The aim of the project is to create an overview of methods of surface modifications used in recent practice and their application in different branches of industry.
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Reduction of Valvetrain Mechanical Losses
Kučera, Pavel ; Píštěk, Václav (referee) ; Novotný, Pavel (advisor)
The topic of this thesis is the mechanical losses in the valvetrain. The purpose is to describe the creation of individual losses and their possible reduction. The main factor of creation of losses is friction. The result of this thesis is to highlight the possible methods to reduce friction and other influences acting on the valvetrain. The main benefit is description various types of surface and design modifications of valvetrains, which are already used or are in development.
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Piston Rings of Modern Diesel Engines
Homola, Petr ; Knotek, Jiří (referee) ; Raffai, Peter (advisor)
This bachelor thesis concentrates on piston rings and is divided into several points. First point deals with the functions of piston rings and with the demands for them, in the second point there is a division according to the type of the ring and constructing solution. Another chapter deals with materials that are used the most when fabricating piston rings and the last chapter deals with the surfacing that is used the most.
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Technology of Galvanic Anodization of Non-ferrous Materials and Its Alloys
Remešová, Michaela ; Hadraba,, Hynek (referee) ; Čelko, Ladislav (advisor)
The thesis is focused on the theoretical description of the technology of anodizing of aluminium, magnesium, zinc and their alloys. In this work, methods for formation of oxide layers and the used chemical processes are described in detail. The experimental part of this work deals with formation of oxide layers on aluminium, magnesium and zinc of high purity under different conditions. Oxide layers of different thicknesses were created on all three experimental materials. Aluminium was anodized in a bath of 10% H2SO4, magnesium in the bath of 1 mol/dm3 NaOH, and zinc in the bath of 0.5 mol/dm3 NaOH. Processes were carried out at laboratory temperature. On the aluminium, continuous oxide layer was formed. Furthermore rule "312" was verified, that can indicatively be used for calculating the thickness of the resulting oxide layer on the aluminium. When using lower current of 0.08 and 0.2 A for magnesium anodizing, dark colored layer was created comparing to higher current of 0.5 A. More rough appearance of the oxide layer was produced with increasing voltage. Further, it was observed for magnesium that the resulting layer comprises of two sublayers. For zinc, black colored layer was created when the voltage 20 V and current from 0.4 to 0.5 A were used. In the layer, two sublayers were also observed. For lower voltage and current (0.05 A, 0.17 V), formation of the oxide layer on the zinc does not occur, but the crystallographic etching was observed.
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Use of wood in consumer products
Zellerová, Michaela ; Chladil, Josef (referee) ; Kalivoda, Milan (advisor)
Bachelor thesis written within the study of mechanical engineering deals with process ofmachiningwood,discussesthematerialanditscharacteristics.Subsequently,itaddressesthetopicofsurfacetreatmentsandpossiblewaysofconnectingmaterials.Theproduct, glasses case, is then developed and its relevant documentation is drawn up.
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Use of wood in consumer products
Zellerová, Michaela ; Chladil, Josef (referee) ; Kalivoda, Milan (advisor)
Bachelor thesis written within the study of mechanical engineering deals with process ofmachiningwood,discussesthematerialanditscharacteristics.Subsequently,itaddressesthetopicofsurfacetreatmentsandpossiblewaysofconnectingmaterials.Theproduct, glasses case, is then developed and its relevant documentation is drawn up.
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Room-temperature semiconducting detectors
Pekárek, Jakub ; Belas, Eduard (advisor) ; Oswald, Jiří (referee) ; Štekl, Ivan (referee)
Semiconducting material CdTe/CdZnTe has a huge application potential in spectroscopic room temperature radiation detection due to its properties. Such detectors can be used in medical applications, homeland security and for monitoring of nuclear facilities. However, the final device quality is influenced by many parameters. One crucial stage in detector fabrication is the proper surface treatment. The detailed study of surface treatments and their effect on final detector device is reported. Another crucial fact is the polarization of the detector caused by high radiation fluxes which negatively affects the use of such devices. The polarization occurs by capturing the photogenerated holes at the deep levels inside the semiconductor. The possible detector depolarization by infrared illumination during the detector operation has been experimentally verified and the obtained results are shown in this thesis. For optimal technology of preparation, it is also necessary to develop the fast characterization method for prepared detectors. The last aim of the thesis is to study the resulting quality of prepared planar and co-planar detectors by transient-current-technique (TCT). TCT is an electro-optical method allowing to determine variety of transport properties of radiation detectors, such as internal electric...
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Technology of Galvanic Anodization of Non-ferrous Materials and Its Alloys
Remešová, Michaela ; Hadraba,, Hynek (referee) ; Čelko, Ladislav (advisor)
The thesis is focused on the theoretical description of the technology of anodizing of aluminium, magnesium, zinc and their alloys. In this work, methods for formation of oxide layers and the used chemical processes are described in detail. The experimental part of this work deals with formation of oxide layers on aluminium, magnesium and zinc of high purity under different conditions. Oxide layers of different thicknesses were created on all three experimental materials. Aluminium was anodized in a bath of 10% H2SO4, magnesium in the bath of 1 mol/dm3 NaOH, and zinc in the bath of 0.5 mol/dm3 NaOH. Processes were carried out at laboratory temperature. On the aluminium, continuous oxide layer was formed. Furthermore rule "312" was verified, that can indicatively be used for calculating the thickness of the resulting oxide layer on the aluminium. When using lower current of 0.08 and 0.2 A for magnesium anodizing, dark colored layer was created comparing to higher current of 0.5 A. More rough appearance of the oxide layer was produced with increasing voltage. Further, it was observed for magnesium that the resulting layer comprises of two sublayers. For zinc, black colored layer was created when the voltage 20 V and current from 0.4 to 0.5 A were used. In the layer, two sublayers were also observed. For lower voltage and current (0.05 A, 0.17 V), formation of the oxide layer on the zinc does not occur, but the crystallographic etching was observed.
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