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Modification of HVOF and cold spray deposited coatings via electron beam technology
Vacek, Petr ; Šiška, Filip (referee) ; Čížek, Jan (advisor)
The aim of this thesis was to modify microstructure and coating-substrate interface of CoNiCrAlY coatings deposited by HVOF and cold spray on Inconel 718 substrates. Electron beam remelting and annealing in a protective atmosphere were used to modify the coatings. Microstructure, chemical and phase composition were analyzed. The effect of beam current, transversal velocity and beam defocus on remelted depth was evaluated. As-sprayed microstructure and chemical composition of coatings were analyzed and compared with remelted samples. The effect of annealing of the as-sprayed and remelted samples was evaluated. Remelted layers exhibited dendritic structure. Chemical composition changed only after remelting of interface and part of a substrate. When only the coating was remelted, chemical composition remained the same. Phases coarsened after the annealing. Chemical composition changed after annealing due to the diffusion.
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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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Formation of Hypereutectic Aluminium Alloys Using Sacrificial Coatings
Gregor, Martin ; Jech, David (referee) ; Čelko, Ladislav (advisor)
Master‘s thesis deals with the forming of hypereutectic aluminium alloys using sacrificial coatings. Literature research is focused on analysing the characteristics of aluminium and its alloys. Attention is also focused to the heat treatment of aluminium alloys and the influence of alloying elements on these alloys. Analysis of characteristics and increase the useful properties of Al - Ni alloys is another object of literary research. Attention is also focused to the analysis of thermal spraying methods by focusing on the principle of individual methods and the characteristics of the coatings made by these methods. The object of experimental part is to prepare the hypereutectic aluminium alloys using sacrificial nickel based coatings. This is an unconventional manufacturing process comprising coating the surface of the aluminium substrate with using HVOF technology and subsequent thermal exposure. Furthermore, the work deals with the metallographic evaluation of prepared samples with a particular focus on the influence of temperature and time of heat treatment on the final structure of the experimental samples.
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Characterization of suspension plasma sprayed coatings deposited using different organic carriers
Dukovský, Daniel ; Toma, Filofteia-Laura (referee) ; Čížek, Jan (advisor)
Cílem této bakalářské práce bylo charakterizovat a porovnat povlaky nanesené plazmovým žárovým nanášením ze suspenze s použitím různých organických nosičů. Teoretická část obsahuje stručný popis běžně používaných metod žárového nanášení a blíže se věnuje technologii hybridního vodou stabilizovaného plazmatu (hořák s touto technologií byl využit pro nanesení povlaků v tomto výzkumu). Druhá polovina teoretické části se zabývá věcným popisem povlaků a metodami nanášení prášku o velikosti částic v řádu nanometrů, kde hraje důležitou roli právě použití suspenze. Experimentální část je zaměřena na vliv použitého solventu v suspenzi na charakteristiky výsledného povlaku. V závěrečné části jsou prezentována a diskutována naměřená data a vyhodnoceny výsledky.
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Restoring of the ventilation shaft generator
Veselý, Libor ; Slaný, Martin (referee) ; Kalivoda, Milan (advisor)
The subject of this work is the repair of an air-handling unit. Possible causes of the problem are analyzed and multiple solutions are proposed. The first variant considers the refurbishment of the damaged component using thermal spray technology, including the choice of the best method. The second solution proposes the manufacture of a new part using machining in the environment of the company. This process requires an intermediate product to be made, and the choice of the correct machines from what the company has available, choice of the right tools and cutting conditions. The technical-economical evaluation compares the the expenses tied with both of the solutions. The chosen repair solution was used for the repair of the air-handling unit.
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Optimization of Machining Parameters Abradable Sprayed used in the Aerospace Industry
Krajkovič, Pavel ; Osička, Karel (referee) ; Kalivoda, Milan (advisor)
This thesis is focused on machining of thermal spray coatings. Particularly on testing of machining parameters and their influence on different types of abradable coatings used in the aerospace industry. The aim of research work is to test the parameters, measure cutting forces by using a dynamometer and their impact on the quality of the machined surface. Determination of the optimal machining parameters for different types of coatings based on results of measurements and the evaluation of surface quality. There are also presented techniques of thermal spray application and methods of coating evaluation. Further it describes a method of measuring cutting forces by using the dynamometer and methods of surface quality evaluation.
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The role of thermal spray parameters on structure and properties of cermet coatings
Vražina, Tomáš ; Čelko,, Ladislav (referee) ; Šulák, Ivo (advisor)
The diploma thesis investigates the influence of thermal spray process parameters on the properties of composite coatings, specifically WC-CrC-Ni and WC-Co-Cr coatings deposed onto an austenitic steel substrate. The main objectives were characterization of sprayed deposition and creation of process maps. The theoretical part included the most important details about the manufacturing process, properties, consolidation and application of cermet materials. The methodical part is devoted to a description of analytical methods and devices used for the characterization of coatings microstructure and its mechanical properties. The practical part provides information acquired from analytical devices. It contains details about surface roughness, hardness, porosity, indentation modulus, corrosion potential and corrosion current density. The chemical composition of coatings and powder mixtures was analyzed by energy dispersive spectroscopy (EDS). For more accurate determination of developed phases X-ray diffraction was used. During the coatings characterization various procedures were developed. It is expected that these procedures would be implemented in another optimization of spraying conditions. Results obtained in the practical part were discussed in discussion and compared with the results from several research studies. Conclusions summarize results obtained in practical part.
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The role of thermal spray parameters on structure and properties of cermet coatings
Vražina, Tomáš ; Čelko,, Ladislav (referee) ; Šulák, Ivo (advisor)
The diploma thesis investigates the influence of thermal spray process parameters on the properties of composite coatings, specifically WC-CrC-Ni and WC-Co-Cr coatings deposed onto an austenitic steel substrate. The main objectives were characterization of sprayed deposition and creation of process maps. The theoretical part included the most important details about the manufacturing process, properties, consolidation and application of cermet materials. The methodical part is devoted to a description of analytical methods and devices used for the characterization of coatings microstructure and its mechanical properties. The practical part provides information acquired from analytical devices. It contains details about surface roughness, hardness, porosity, indentation modulus, corrosion potential and corrosion current density. The chemical composition of coatings and powder mixtures was analyzed by energy dispersive spectroscopy (EDS). For more accurate determination of developed phases X-ray diffraction was used. During the coatings characterization various procedures were developed. It is expected that these procedures would be implemented in another optimization of spraying conditions. Results obtained in the practical part were discussed in discussion and compared with the results from several research studies. Conclusions summarize results obtained in practical part.
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Characterization of suspension plasma sprayed coatings deposited using different organic carriers
Dukovský, Daniel ; Toma, Filofteia-Laura (referee) ; Čížek, Jan (advisor)
Cílem této bakalářské práce bylo charakterizovat a porovnat povlaky nanesené plazmovým žárovým nanášením ze suspenze s použitím různých organických nosičů. Teoretická část obsahuje stručný popis běžně používaných metod žárového nanášení a blíže se věnuje technologii hybridního vodou stabilizovaného plazmatu (hořák s touto technologií byl využit pro nanesení povlaků v tomto výzkumu). Druhá polovina teoretické části se zabývá věcným popisem povlaků a metodami nanášení prášku o velikosti částic v řádu nanometrů, kde hraje důležitou roli právě použití suspenze. Experimentální část je zaměřena na vliv použitého solventu v suspenzi na charakteristiky výsledného povlaku. V závěrečné části jsou prezentována a diskutována naměřená data a vyhodnoceny výsledky.
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Restoring of the ventilation shaft generator
Veselý, Libor ; Slaný, Martin (referee) ; Kalivoda, Milan (advisor)
The subject of this work is the repair of an air-handling unit. Possible causes of the problem are analyzed and multiple solutions are proposed. The first variant considers the refurbishment of the damaged component using thermal spray technology, including the choice of the best method. The second solution proposes the manufacture of a new part using machining in the environment of the company. This process requires an intermediate product to be made, and the choice of the correct machines from what the company has available, choice of the right tools and cutting conditions. The technical-economical evaluation compares the the expenses tied with both of the solutions. The chosen repair solution was used for the repair of the air-handling unit.
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