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Reducing friction losses of piston rings
Csintalan, Radoslav ; Novotný, Pavel (referee) ; Svída, David (advisor)
This diploma thesis deals with the possibilities of reducing the friction losses of the first sealing piston rings of the VW Group 1.5 TSI, 110kW engine. The first part of the thesis theoretically deals with the issue of piston rings in terms of their classification. Reduction of friction losses is ensured by PVD and PECVD coating technology. The second part of the thesis describes the production of coated piston rings. Measurements are performed on the created coatings, which are compared and evaluated in the conclusion at the end of the thesis.
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Coating of tools by the PVD HiPIMS technology
Havlíková, Tereza ; Ohnišťová, Petra (referee) ; Píška, Miroslav (advisor)
This bachelor’s thesis is aimed on the study of PVD coatings of tools with a focus on HiPIMS (High Power Impulse Magnetron Sputtering) technology. As part of the research, the PVD coating methods are presented, then the basic physical processes and characteristics of magnetron sputtering are described and finally the HiPIMS technology is analysed. The aim of the experimental part of this study is to evaluate (Al,Ti)N coating deposited by HiPIMS technology on a wire drawing die. For coated and uncoated die, the wear of the die, surface quality and thermal impact on the wire are observed and compared.
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Reducing friction losses of piston rings
Csintalan, Radoslav ; Novotný, Pavel (referee) ; Svída, David (advisor)
This diploma thesis deals with the possibilities of reducing the friction losses of the first sealing piston rings of the VW Group 1.5 TSI, 110kW engine. The first part of the thesis theoretically deals with the issue of piston rings in terms of their classification. Reduction of friction losses is ensured by PVD and PECVD coating technology. The second part of the thesis describes the production of coated piston rings. Measurements are performed on the created coatings, which are compared and evaluated in the conclusion at the end of the thesis.
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Fabrication and structuring of a thin vanadium dioxide layer for nanophotonics
Spousta, Jiří ; Musálek, Tomáš (referee) ; Rovenská, Katarína (advisor)
Vanadium dioxide is becoming frequently used in tunable metasurfaces, mainly due to its easily achievable insulator to metal phase-transition, occuring at around 67°C. This thesis deals with the optimization of thin VO2 layer fabrication process and specifically with e-beam evaporation and ion beam-assisted sputtering. The phase change of VO2 layers was optically characterized -- mostly, we measured the thermally-dependent transmissivity of our layers. In ion beam-assisted sputtering, we implemented a new process for yielding thin VO2 layers which uses in situ annealing during the deposition. Layers fabricated with this newly implemented process demonstrate a clear phase transition typical for VO2.
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Modern surface coating of cutting tools for machining
Tříletý, Vlastimil ; Ohnišťová, Petra (referee) ; Píška, Miroslav (advisor)
This bachelor thesis consists of two main parts. The theoretical part generally describes methods for coating cutting tools, wear mechanisms of cutting tools and experimental evaluation of coating properties and evaluation of tool life. The practical part is focused on the evaluation of tool life based on the observation of the development of wear using a scanning electron microscope.
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Deposition and analysis of AlCrN coatings
Drásalová, Kateřina ; Juliš, Martin (referee) ; Klakurková, Lenka (advisor)
The topic of this thesis is the deposition process and methods of quality assessment of AlCrN surface coatings produced by methods of (i) magnetron sputtering, (ii) magnetron sputtering with arc enhanced glow discharge, and (iii) high power magnetron sputtering with the movable magnetic field. The main focus is placed on categorizing properties of the produced coatings based on the production method (which vary in the ionization level). Qualities of the surface coatings are assessed by adhesion and cohesion parameters testing of coarseness using AFM (Atomic Force Microscopy), depth measuring using a calotest, measuring internal tension using the Bent Strip Method and Instrumented indentation test for hardness.
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On the analyses of cutiing tools coated with PVD coatings
Malý, Martin ; Osička, Karel (referee) ; Píška, Miroslav (advisor)
In this diploma thesis, literary research about drilling and coating technology focused on PVD coatings was performed. Furthermore, there is an overview of cutting materials. In the experimental part of the work, the attention is dedicated to tests of twist drills from cemented carbide and high-speed steel materials. For these drills, the feed force Ff and the cutting moment Mc were measured when drilling into austenitic stainless steel. At the end of this work, the technical and economic evaluation of the practical part is presented.
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Digital Image Steganography
Kolarčík, Tomáš ; Šimek, Václav (referee) ; Strnadel, Josef (advisor)
This bachelor thesis deals with digital image steganography and implements some of the available methods. This thesis describes steganography on a general level, it's history and it's current form. It also shows it's classification according to the type of carrier, the classification of the methods according to the style of hiding data and the influence of the hidden information. The primary subject of this thesis is image steganography, where facts that allow imperceptibly hide data inside image are described. A great part of this thesis is dedicated to the characteristics of the methods, which we observe and to the methods themselves. All of the methods described are implemented in a graphical and console application. The created application provides multiple image formats for hiding. In the last part, testing is performed in terms of capacity, imperceptibility and robustness.
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Modern methods of coating of cutting tools and their application
Kolenič, Michal ; Sliwková, Petra (referee) ; Píška, Miroslav (advisor)
This study is aimed on PVD coatings with focus on one of the more advanced PVD methods – high-power impulse magnetron sputtering (HIPIMS). This study aims to describe mechanical and structural proprieties of multiple types of PVD coatings. Experimental part of this study aims to analyse mechanical proprieties and durability of cutting tools with coatings created using HIPIMS methods. The experimental part of this work results in comparison of cutting moments of cutting tools coated with TiN and TiAlN using HIPIMS and a cutting tool without coating.
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