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Zinc coatings
Zdařil, Lubor ; Trčka, Josef (referee) ; Zmrzlý, Martin (advisor)
The aim of this work is a description of corrosion as a major phenomenon in the degradation of the material and the description basic types of corrosion. Then the material protection possibilities are described using a suitable choice of surface treatment. From the wide field of coating systems, electrodeposited zinc based alloys coatings were emphasized. theirs subsequent increase of corrosion resistance by applying powder coatings. Alloy coatings that are in the focus of recent research were discussed.
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Sizing of the waves geometrical parameters fabricated on the sheet metal die
Stupárek, Daniel ; Forejt, Milan (referee) ; Samek, Radko (advisor)
This thesis approaches the problem of the return of the original geometric shape of the wave which is created on die panels. Die is used as a structural feature of the fiber-cement roofing material in its shipment in the production line. Based on the study of the theory of cold formed sheet metal determine the actual status in the plant. The method of calibration was designed from the collected informations about the original manufacturer of sheet metal panels. Under this proposal and calculation of the required forming power for the recalibration wave in the factory device for the die calibration was designed and constructed. Equipment calibration was performed on two types of corrugated panels and the result fulfilled the theoretical assumptions. In conclusion is processed technological-economic evaluation and the accompanying drawings.
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Welding of heat - resistent steels by narrow gap SMAW method.
Lukosz, Ondřej ; Kubíček, Jaroslav (referee) ; Daněk, Ladislav (advisor)
LUKOSZ Ondřej: Welding of heat - resistent steels by method SMAW into the narrow gap. The project elaborated in frame of engineering studies branch 2307. The project is submitting design of technology production of the weld procedure creep metal. It uses in manufactory power equipment. The power equipment, the type of steam turbine, uses steel 30CrMoNiV 5-11. The welding into the narrow gap has its specifics. The most important parameter is the choice of flux and filler metal. We must decide appropriate flux for convenient disposing of slag. Based on the literature study these problems were proposed the specified welding procedure, appropriate flux and appropriate additional material. For the experiment was selected appropriate temperature of preheating.
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Design of cutter head with Harmonic-Drive application
Tkadlec, Dušan ; Dosedla, Michal (referee) ; Holub, Michal (advisor)
This master´s work deal with design two axis cutter head with possible variants drive of axis. The part of this work is also technical– economics valuation of single variants, calculation torque and force from motor head and design taking head in two axis. Cutter head should be applicated to boring and cutting headstock given to type with posibility of adaptive exchenges spindle.
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Polymer nanocomposites with PMMA matrix
Kostková, Jana ; Žídek, Jan (referee) ; Jančář, Josef (advisor)
This bachelor thesis deals with s study of mechanical and viscoelastic properties of nanocomposites with PMMA matrix filled with different types of surface-modified silica, which differed by the specific surface area, surface treatment and particle size. Nanocomposites were prepared by dissolving, where nanofillers were injected into the dissolved matrix. Nanocomposite samples were tested in tensil and viscoelastic properties were determined till the softening point by dynamic-mechanical analysis (DMA). All types of nanofillers had almost no effect on tensile modulus of nanocomposites at room temperature (it was not reduced) one type of silica at a content 2 %, which was also confirmed by the DMA. The temperature DMA measurements showed that samples containing 2 % of silica were generally thermally more stable compared with nanocomposites containing 1 % of silica. Storage modulus of nanocomposites, except two ones, were similar or lower such pure PMMA to temperature 66 C, then the trend reversed. Loss modulus of all samples was one order of magnitude lower then the elastic modulus.
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Cemented carbides and theirs effective use
Dembek, Jiří ; Sedlák, Josef (referee) ; Humár, Anton (advisor)
This diploma thesis is aimed on cutting tools made of cemented carbides. It characterizes marking, production and properties of non-coating and coating cemented carbides and describes the latest trends in coating. Target of this diploma thesis is comparison of assortment of two important world’s producers and one Czech producer in term of used productive technologies, products microstructure, coatings types, coatings methods and possibilities of their usage. Cutting data were evaluated and compared from obtained technical knowledge, which were recommended by chosen producers for effective turning application of their cutting tools. Recommended cutting speeds were found out for specific type of cutting material according to ISO, width depth of cut and for specific values of feeds per revolution.
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Technology of manufacture and treatment of medieval arrowhead
Kašpar, Jan ; Stránský, Karel (referee) ; Stránský, Karel (referee) ; Doležal, Pavel (advisor)
This thesis analyses issue of manufacture, typology and use of medieval arrowheads. In theoretical part describe historical evolution of bow and his archaeological discovery in Europe, especially from medieval times. After that is revealed historical evolution of arrowheads and describe their typology. In next chapters are mentioned ways of iron production, mainly in early medieval times and also describe technology of manufacture different types of arrowheads. There is a characterization of medieval arrow, his construction and characteristics. Continuously in this background research are revealing questions of penetration depend on the various types of arrowheads, which are testing on the most known types of armour like chainmail or breast plate. In experimental part of this paper are metallographicaly analyzing archaeological discoveries from the early and late medieval times. Conclusions about their manufacturing, treatment and possibilities of use are built on knowledge about arrowheads structures, hardness and shapes.
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Evaluation of corrosion on selected aluminium alloys
Skýba, Pavel ; Tulka, Jaromír (referee) ; Pacal, Bohumil (advisor)
The thesis focuses on the corrosion research of AlCu4Mg1 aluminium alloys of square shape and sheet metal coated in 99.5% aluminium. The theoretical part deals with the characteristics of aluminium, the classification and naming of aluminium alloys and the impact of admixtures on aluminium alloys. In the following chapter a general introduction to metal corrosion, its differentiation according to the type of corrosion attack, mechanisms of corrosion, the impact of corrosive environment, according to the choice of anti-corrosion protection, etc. is given. The main part is devoted to the corrosion of aluminium with a special importance of the impact of admixtures on aluminium alloys, the types of corrosion attack, the impact of corrosive environment as well as of the anti-corrosion protection of aluminium alloys. The corrosion tests in controlled atmosphere are considered in the next chapter, while the last one deals with the evaluation methodology of the process of corrosion. At the beginning of the experimental part all the used samples and materials are introduced. The thesis continues then with an overview and a description of the methods used for experiments. The measurement procedure and the results of the experiments are presented in the following chapter that focuses on the metallographic analysis of the aluminium alloy samples before the experiment and after the corrosion attack. The main part of the chapter deals with the dependence of corrosion speed of the individual aluminium alloy samples on time after being exposed in the climate chamber and the salt fog chamber
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Vodní a hybridní plazmatrony s plynovou a vodní stabilizací
Hrabovský, Milan
Plasma torches with water-stabilized arc (Gerdien arc) are utilized in plasma processing for specific applications. In water-stabilized torches an oxygen-hydrogen plasma jet is produced. The torches are characterized by very low mass flow rates and high power. Plasma enthalpy is thus several times higher than enthalpy of plasmas generated in gas-stabilized torches. High enthalpy is accompanied by very low plasma density. Also other plasma parameters substantially differ from the ones in gas torches. New type of plasma torch with combined stabilization of an electric arc by water vortex and gas flow was investigated. This hybrid water/gas stabilization offers possibility of adjustment of plasma jet parameters in a wide range from high enthalpy, low density plasmas typical for liquid stabilized torches to lower enthalpy, higher density plasmas generated in gas stabilized torches.
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