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Influence of pyrrolidone derivates on alkyd and polyurethane coatings.
Klímová, Edita ; Molliková, Eva (referee) ; Tulka, Jaromír (advisor)
The aim of this thesis was to append data on chemical resistance of coatings made of paints based on alkyd and polyurethane resins. In the theoretical part, relevant information on coatings, preparation of their systems, theory of solubilization and properties of solvents were collected and organized. Three N-derivates of pyrrolidone were chosen for the practical part. Their influence on particular alkyd and polyurethane coatings was studied with emphasis on time course of coatings degradation.
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Surface treatments in mechanical engineering
Čudová, Monika ; Kubíček, Jaroslav (referee) ; Žák, Ladislav (advisor)
The project was developed within the bachelor study presents experimental verification of two given varnishes. They are applied on a specially made plate. It was based on literary studies of corrosion coatings issues - coatings and practical tests. The samples were painted and tested according to the standards. The samples were tested on adhesion of varnishes, bending test and salt stray test. Finally all tests were evaluated.
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Modification of coating-substrate interface character of thermally sprayed coatings using electron beam technology
Mareš, Jiří ; Moravčík, Igor (referee) ; Čížek, Jan (advisor)
Tato práce je zaměřena na modifikaci charakteru rozhraní substrát-nástřik NiCrAlY povlaků nanesených pomocí technologie vodou stabilizované plazmy na substráty z oceli S235JRC+C. Přetavení žárové vrstvy elektronovým paprskem bylo zvoleno jako technologie pro modifikaci a dvě různé modifikace byly zkoumány. V práci byl proveden pokus o stanovení vlivu modifikací na adhezní vlastnosti nástřiku. Dále jsou v práci prezentovány analýzy mikrostruktury, fázového a chemického složení a mikrotvrdosti ve stavu před a po modifikaci. Během studie bylo zjištěno, že dochází ke změnám fázového složení jak během depozice, tak během modifikace elektronovým paprskem. Modifikace elektronovým paprskem způsobila roztavení oxidů původní mikrostruktury nástřiku, které následně rekrystalizovaly na povrchu modifikované vrstvy. Dalším získaným poznatkem bylo, že dochází ke snížení mikrotvrdosti po modifikaci, což bylo způsobeno odstraněním oxidů z mikrostruktury a promícháním materiálu substrátu a původního nástřiku. Adheze nástřiků v as sprayed stavu byla kvantifikována. V případě nástřiků modifikovaných elektronovým paprskem přesná kvantifikace nebyla možná, z důvodu předčasného porušení na rozhraní nástřik-adhezivní pojivo během adhezních testů.
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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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Cold Spray coatings on high strength steels
Šesták, Stanislav ; Čupera, Jan (referee) ; Řehořek, Lukáš (advisor)
This bachelor’s thesis focuses on possible applications of the Cold Spray additive technology in context of high strength steels. The theoretical part of this work represents an extensive research on the topic of Cold Spray technology, showing connections between many of the mechanisms of this technology. This part also focuses specifically on high strength steels, their types, microstructures and properties. The experimental part of this work examines four samples of Cold Spray coatings on a high strength steel. After depositing these coatings, microstructure and microhardness analysis are provided.
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Powder feeding analysis in RF-ICP
Zlatník, Rostislav ; Veverka, Jakub (referee) ; Čížek, Jan (advisor)
The work is focused on the problematics of inductively coupled plasma, which is used for deposition of layers. We focused on two goals in the work. The first one focused on powder feeder, which is working on the vibration principle and is used in an apparatus that is using inductively coupled plasma. The aim is to determine its properties, dependence on different input parameters and working conditions. Is important to verify the suitability of its use for this kind of application. The assumption was to find the ideal configuration of the feeder for the given powder. After an overall assessment of the feeder properties, it was recognized as inappropriate for this application. The second goal is to spray tungsten layers with three different tungsten powders. Layers made with an inductively coupled plasma technology delivers promising results, but this issue needs to be intensively addressed in the future.
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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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Coating methods for cutting tools
Tuna, Jaroslav ; Prokop, Jaroslav (referee) ; Humár, Anton (advisor)
This diploma thesis is aimed on methods of the coating cutting material (cemented carbide, cermets, cutting ceramic, super hard materials) and evalutation individual method regarding technological posibilities of deposition of hard coatings a their mechanical, thermal and che-mical properties. The task of the work is full elaboration obtained technical knowledges and mainly evalutation a comparison of the work conditions (kind of the cutting materials, cutting conditions) that selected producers recomended for effective turning aplications of the coa-tings cutting materials.
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