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Manufacture of gastronomic equipment of stainless steel
Macková, Ivana ; Varhaník, Matúš (referee) ; Kalivoda, Milan (advisor)
The bachelor thesis seals with corrosion, stainless steels and surface treatments of steels, which prevent corrosive disruption of the material. Furthermore, the work deals with the design of the production of non-rotating component with a flange made of austenitic stainless steel X5CrNi 18-10. A blank is cut out on sheet shears. A blank is formed into the desire shape on a CYS 320 press by deep drawing technology, and later a flange is cut on LEXN 100 C press. The economic evaluation of production is set at a model situation of 100 000 pcs/year.
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Monitoring Of Bridges Corrosion Level
Krejčí, Jakub
Corrosive damage level of bridge constructions becomes high discussed topic with regard to some recent incidents. Current system of inspections is based mostly only on visual inspections in the Czech Republic. Our solution proposes to build-in a humidity sensor inside a bridge structure to detect leaking water and damage level during long period. Text focuses on description of basic principles of humidity measurement and performed experiments with sensors implemented in porous material showing possibility of measurement inside a structure. Finally, a market research of commercially available sensors is documented with narrowing selection suitable for this application.
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Materials For Biodegradable Bones Based On Fe
Hrabovský, Jan
The thesis deals with biodegradable bone implants which must have good mechanical properties and also good compatibility with the human body. The thesis contains literary research in the area of bone physiology, biogenic materials and implants for the human body. The thesis focues on the selection of suitable materials for biogenic implants.
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Diagnostics of bridge structure
Nápravník, Petr ; Žítt, Petr (referee) ; Láník, Jaromír (advisor)
This bachelor´s thesis deals with construction-technical survey of a highway bridge no. D1-243 across Ripska street at suburbs of Brno. Theoretical part contains bridge terminology, inspections, problematics of prefabricated beams I-73, construction-technical survey and description of laboratory tests. Practical part deals with making of a construction-technical survey, evaluation of construction parts and a summary of results.
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Survey and Diagnostics of Reinforced Concrete Structure
Haloun, Jan ; Heřmánková, Věra (referee) ; Anton, Ondřej (advisor)
The first part of this diploma thesis is about late and current methods used in Engineering surveys. The theoretical part is focused on description of individual testing methods and their evaluation based on relevant standarts. Detailed description of diagnostic methods is dependent on methods used in a practical part. The practical part is focused on defining of material characteristics of used materials and way of reinforcing of reinforced concrete elements. Based on those defined pieces of information the static recalculation of girder and pile was made.
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Plasma cleaning of corroded plumb objects
Bubnová, Kateřina ; Grossmannová, Hana (referee) ; Krčma, František (advisor)
This bachelor thesis deals with the application of low-pressure hydrogen plasma to lead corrosion products. There are many historical objects and these objects require careful removal of corrosion layers. Therefore, it is necessary to optimize the treatment process in order not to destroy real historical artefacts in the future. This work is focused on lead, which has not been explored by this method yet. Model samples with corrosion were prepared for comparison and these samples corrode in vapors of concentrated acetic acid and formic acid. There were three working temperatures for plasma chemical treatment because of the low lead melting point and the atomic heating. Argon-hydrogen plasma and hydrogen plasma was applied to 12 corroded samples during the experiment. Process progress was monitored by optical emission spectrometry and surface analysis was performed by SEM, XRD and EDX analysis. The results of these analyzes showed that the most appropriate temperature for plasma chemical treatment was 130 ° C. Based on the obtained results many suggesstions and ideas were obtained for the future research like using of pulse mode and gas composition.
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Preparation of historical binders with high resistance to ambient influences
Nehybka, Josef ; Palovčík, Jakub (referee) ; Opravil, Tomáš (advisor)
This master’s thesis is focused on preparation of the mortar mixtures inspired by roman cement with a great resistivity against the corrosion environment, especially a seawater. There were prepared samples of a roman cement containing of pure lime and various artificial pozzolans and natural tuff which were used as pozzolan admixtures. The task of this work is to explore possibility of using pure lime and for example pozzolan admixture which can resist against the corrosive environment like a roman cement. There were prepared a lot of various samples which were tested separately on their mechanical characteristics before and after their exposure of the influence of the corrosive environment. There were used X-ray diffraction analysis for the characterization of a phase composition of the raw materials and some selected samples.
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Galvanic plating of magnesium alloy with Ni-P bond coat
Zahálka, Martin ; Kosár, Petr (referee) ; Wasserbauer, Jaromír (advisor)
Cílem této diplomové práce jse najít nejnižší možnou tloušťku nikl-fosforového povlaku, který může být galvanicky pokoven mědí bez defektů na horčíkové slitině, nikl-fosforového nebo měděného povlaku. V teoretické části jsou shrnuty poznatky o hořčíkových slitinách a jejich korozi. Navíc se teoreticá část zaměřuje na popis procesu bezproudého niklování a elektrochemického pokovování mědí a jejich porovnání. Na konci teoretické části je shrnut současný výzkum o elektrochemickém pokovování hořčíkových slitin. V experimentální části byl popsán proces přípravy povlaků Ni-P a Cu na horčíkové slitině AZ91. Na jedné vrstvě a dvojité vrstvě Ni-P povlaku byla provedena elektrodepozice mědi. Navíc byl diskutován vliv předůpravy před samotnou elektrodepozicí mědi. Za účelem zjištění korozních vlastností vzorků byl vykonán potenciodynamický test. Následně byly připraveny metalografické výbrusy jednotlivých vzorků a pomocí světelného a rastrovacího elektronového mikroskopu byla provedena charakterizace. Na konec bylo zjištěno prvkové složení jednotlivých povlaků pomocí EDX analýzy.
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Complete characterization of the ceramic-based hot-coated coating on the AZ91 magnesium alloy
Plevová, Kateřina ; Doskočil, Leoš (referee) ; Wasserbauer, Jaromír (advisor)
The diploma thesis is focused on the study of the thermal sprayed coating consisting of the NiCrAlY alloy bond layer and the partially stabilized zirconium oxide (8YSZ) top layer on the AZ91 magnesium alloy. The theoretical part deals with the structure of the alloy AZ91, NiCrAlY and partially stabilized zirconia. Furthermore, the methods of thermal spraying and the function and properties of thermal barrier coatings are summarized. The experimental part deals with the characterization of the thermal sprayed coating and the AZ91 alloy in terms of elemental, structural and phase composition. Optical and electron microscopy, EDS and XRD analysis were used for characterization. Electrochemical properties were investigated in~3.5% sodium chloride solution by potentiodynamic polarization. The mechanical properties (hardness, coefficient of friction) of the substrate and coating were measured using a hardness tester and tribological tests.
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Advanced Composite Structural Steels for Applications in Heavy Liquid Metals
Husák, Roman ; Haušild, Petr (referee) ; Vilémová,, Monika (referee) ; Hadraba, Hynek (advisor)
Doctoral thesis was focused on preparing of new advanced ODS steels for use in heavy metal liquids enviroments. Possibility of new course for creating oxide dispersion in microstructure was verified by the course of internal oxidation of elements. By the internal oxidation method were prepared new ODS steels strengthened by complex oxides which were created by elements of IIIB and IVB group of elements. Based on analysis of damage ODS steels in LBE were designed surface protection of ODS steel by the oxide layer. The ODS steel protected by oxide layer was subjected to a corrosion test in LBE. For the experiments were chosen class of chromium steels: ferritic-martensitic steel 9Cr1WMnVTa and ferritic steels 14CrWTi and 17Cr1Mo. Steels without oxide dispersion and steel strenghtened by the dispersion based on Y-Ti-O oxides were prepared. On the steels were made series of mechanic tests which should reveal the effectivity of oxide dispersion on the strenght of steel prepared by the internal oxidation method and by the direct addition of oxide elements. It was found that significantly harder oxide material couldn't be fully disrupted through the mechanical alloying and fine oxide dispersion couldn't be created. There was verified fine oxide dispersion could be created by the internal oxidation method and by the direct adding of oxide elements. Same kind of steels strenghtened by new kind of complex oxides based on Y, Ce, Hf, La, Sc and Zr were prepared. The chemical analyses have proven that all added elements could created complex oxide by the reaction with yttrium. The computational analyses for observing of matrix influence and oxide phase influence on strenghtening of steels were performed. These computational analyses were based on microstructural analyses of ODS steels. There was found that the oxide particles could very effectively improve strenght of steels at room temperature and especialy at high temperature. Based on corrosion tests of 14Cr ODS steel in liquid Pb and LBE enviroment were designed surface protection of ODS steel. The effectiveness of protective layer was verified by the high temperature corrosion test of PM2000 in LBE. No damage of oxide layer was observed although Pb and Bi diffused through protective layer.
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