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High temperature coatings for gas turbine blades
Chýlek, Radomír ; Brázdil, Marian (referee) ; Šnajdárek, Ladislav (advisor)
The purpose of this bachelor thesis is the overview of technology of high temperature coatings for gas turbine blades. The familiarization with properties of individual coatings, their capabilities to increase the blades durability and their resistance to damage and temperature influences are emphasized in this work. The potential of significant increase of gas turbines efficiency using different types of coating and cooling of the blades was evaluated in this thesis. Additionally the individual coating techniques are described and compared. Last but not least, this thesis contains closer description of the state-of-the-art thermal barrier coatings including the characteristics required for the following computing part. The computing part deals with calculation of heat transfer through the blade. The conclusion is dedicated to the future use of the coatings from the author's perspective.
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Deposition of MMC-type composite coatings on steel substrates using the Cold Spray method
Šesták, Stanislav ; Doubrava, Marek (referee) ; Řehořek, Lukáš (advisor)
The Cold Spray method is a modern coating method characterized by several interesting advantages and drawbacks. One of the most significant drawbacks is the difficult manufacturing of materials with limited ductility. This work is dedicated to this issue, and its main objective is the development of tribological coatings for high-temperature applications on steel substrates. Extensive research focused on the nature of the chosen deposition method and its specifics in the context of materials with limited ductility is provided and concluded by a set of methodical approaches of deposition, which are verified in the experimental part of this work. The experimental part focused on processing Ni-B4C and Ni-SiC composite coatings, in which the reinforcement particle volume fraction was chosen as 20 and 40 %. All coatings were deposited on 42CrMo4 steel substrates. The analysis of the coatings consisted of microstructure evaluation (using optical and electron microscopy) hardness testing and adhesion testing. The Ni-SiC coating consisting of 40 vol.% SiC particles showed the best properties; compared to other coatings it offered the highest microstructural quality and microhardness values. This coating was found suitable for the chosen application, and further suggestions on improving the quality of this coating were provided in this work’s conclusion.
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Metody ochrany karoserií vozidel proti korozi
Ulver, Marek
This bachelor thesis deals with the issue of corrosion and ways of corrosion protection in terms of car bodyworks. In the first part there is described the theoretical basis of corrosion systems with focus on identification of the different types of corrosion. This part is followed by a description of the protection methods against corrosion. The second part deals with the issue of structural materials which are used in car industry. The last part deals with the anti-corrosion treatment of car bodywork, where the attention is paid to technologies used in mass production.
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Corrosion protection by means of plasma spraying coatings
Bartoněk, Daniel ; Řehořek, Lukáš (referee) ; Jan, Vít (advisor)
This thesis is focused on making study of technologies used for applying metal coatings as corrosion protection and commonly used materials. By means of metalographic analysis compare microstructures of coatings thermal spraying by zinc based alloys. The thesis is describing basics of corrosion, means of corrosion protection and methods used for making zinc coatings for corrosion protection. Experimental part is comparing coatings made by thermal plasma spraying and thermal spraying with use of electric current.
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surface finish for the container CASTOR
Tomek, Jan ; Kubíček, Jaroslav (referee) ; Žák, Ladislav (advisor)
Master’s thesis deals with the problems of the inner surface finish design for the CASTOR container. In the theoretical part are analyzed properties of metallic surfaces with their defects and various options of surface finishes for increased protection. The practical part of the thesis is focused on the design of appropriate technologies for specific requirements of the surface finish for the CASTOR container, creating test samples and their evaluation.
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Embrittlement of TiAl intermetalics induced by surface oxidation
Fukátková, Pavla ; Jan, Vít (referee) ; Dlouhý, Ivo (advisor)
This work aimed to study the effect of surface oxidation of TiAl intermetallic alloys, its fracture behavior and study the formation and stability of picked coatings that could prevent these phenomena. ?-TiAl alloy (Ti46Al7Nb) was examined by three different coatings (AlCr, AlCrN and AlCrNAg). Firstly, it was carried out short-term exposure to high temperature in an inert atmosphere for all coatings. Secondly, there were experiments of cyclic exposure to high temperature in normal atmosphere and isothermal high-temperature exposure in a normal atmosphere. During high-temperature experiments in normal atmosphere mass gain was measured and it was monitored a surface texture. Finally, the most promising coatings were chosen, and those were evaluated in bending strength.
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Optimization of indexable inserts use in production line
Kocúrek, Ondřej ; Novák, Zdeněk (referee) ; Humár, Anton (advisor)
This thesis deals with a summary of different types and characteristics of coatings used for increasing the lifetime of cemented carbide tools. Besides, the thesis includes solving the issue regarding edge chipping during machining interrupted pipe ends at the pipe line, selecting a new type of indexable inserts and indexable inserts holders to increase line productivity and decrease tool costs in the related operation.
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Corrosion resistance of surface treatments by polysiloxane paint systems.
Kulhanová, Veronika ; Molliková, Eva (referee) ; Tulka, Jaromír (advisor)
Influence of atmospheric and chemical environments on metal products leads usually to the corrosion damage. This master´s thesis deals with way to protect metals from corrosion, especially by polysiloxane coatings in combination with coatings containing zinc. Corrosion resistance of created coatings systems is tested by laboratory accelerated tests in corrosion chamber, where the natural atmospheric conditions are simulated. Chemical resistance in selected environments is verified by drop test. Quality characteristics coatings – thickness, adhesion to the underlying material, hardness and stability of the coating colour and gloss are evaluated too.
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