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Surface melting and possible alloying of cast iron with lamellar graphite by electron beam
Abu Khait, Yosef ; Kouřil, Miloslav (referee) ; Pacal, Bohumil (advisor)
In this thesis, the structural and mechanical changes, which took place in flake graphite cast iron after electron beam surface melting and chrome-nickel surface alloying, were studied. Furthermore, the effect of set parameters on properties and depth of the melted and alloyed region is also analyzed. In the experimental part, the analyzed microstructures, micro-hardness and the distribution of elements after melting and alloying, were presented. Structural differences of material regions caused by melting were described based on microstructures. In the end of diploma thesis, the conclusions of using EB technology for surface melting and alloying were discussed.
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Rotary flash hardening with help of electron beam and laser radiation
Klusáček, Martin ; Jan, Vít (referee) ; Kouřil, Miloslav (advisor)
This master thesis deals with surface hardening of steels, especially with rotary flash hardening of 42CrMo4 steel (WNr 1.3563, ČSN 15142). In this method homogenous heating of whole surface occurs during a very fast rotation of the component. In the theoretical part of this thesis the most common methods of surface hardening are described, with focus on laser and electron beam technologies. In the experimental part special device for this application was constructed. Rotary flash hardening was done using different radiation source and experimantal device parameters. The hardened surface layer of maximal thickness of 0,7 mm and width of 5,6 mm was achieved using laser beam. Results with electron beam were way better, because this technology allows to control the distribution of power along the beam width in order to improve the width/thickness ratio of hardened layer. Using this method maximal layer thickness of 1,4 mm and width of 13,4 mm was achieved.
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Aerodynamic design and analysis of "Twin Shark" glider
Krmela, Luděk ; Kouřil, Martin (referee) ; Popela, Robert (advisor)
The thesis contains determination of real aerodynamics characteristics of PW09-135 flap airfoil with help of calibration method via CFD, followed by accomplishment of CFD analysis of parts and the whole Twin Shark glider. Detailed research and optimization was made to flow field quality of fuselage and wing fuselage junction. On the basis of CFD solution was determine a stability control, static margin and angle of attack of a horizontal stabilizer. The thesis concludes an evaluation of results applicability in praxis.
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Surface treatment of selected steels using electron beam
Oríšek, Petr ; Jan, Vít (referee) ; Kouřil, Miloslav (advisor)
The thesis aims for the surface treatment of materials using electron beam. It includes a literary research describing physical principle and properties of the electron beam. This research also presents possible influencing of the beam and describes the construction of the device that generates the beam. Various applications of the electron beam for the material treatment are presented in the second part of the paper. Within this thesis an experiment with the heat treatment of the steel surface by the electron beam has been realized. The experiment was aimed at creating a layer as deep as possible without melting the surface. The results and their evaluation are presented in the experimental part of the thesis. The attention is also paid to selected process parameters.
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Structure and properties of electron beam penetration produced in steel AMS 5659
Říčan, Daniel ; Foret, Rudolf (referee) ; Kouřil, Miloslav (advisor)
This master thesis deals with the electron beam welding of the AMS 5659 steel used in industry for special hydraulic cylinders (Fig. 1). A theoretical analysis of electron beam welding and analysis of the influence of selected welding parameters on penetration characteristics are in the first part of the thesis. The second part contains an evaluation of the implemented experimental penetrations on samples of the steel in the hardened condition H1025 and after solution heat. It was also done a properties assessment of the same samples that were been hardened again. The light microscopy (SM), the scanning electron microscopy (SEM) and the measurement method of hardness according to Vickers were used for evaluation and comparison of the steel properties in the region of penetration and the heat affected zones properties.
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Information System Assessment and Proposal of ICT Modification
Kouřil, Martin ; Jura, Pavel (referee) ; Koch, Miloš (advisor)
This master thesis is aimed at information systems and a correct method of their selection. The theoretical part introduces the dilemma within information systems, ERP systems, their examination and selection. Fisrtly there are some analyses of the existing system operating in company and after that follows own solution which consists of information strategy determination and the selection of convenient information system.
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Methodology of electrolytic metal cleaning methods using an electrolyte based on modified gels
Rapouch, Karel ; Hájková, Kateřina ; Selucká, Alena ; Perlík, Dušan ; Kouřil, Milan
The methodology aims to provide simple instructions for conservators-restorers on how to set suitable conditions for local and gentle cleaning of corrosion products of silver and copper, in order to avoid mechanical damage to the surface of the object and influence of surrounding (especially organic) materials in the case of multi-material objects of a cultural heritage. As part of the methodology, various gels were studied in terms of their physico-chemical properties and their compatibility with chemicals from which an electrolyte can be prepared for the electrolytic cleaning of metal surfaces. Artificially patinated samples and selected real objects were used for the experiments. Furthermore, the possibility of using gel electrolytes for the study of corrosion products by the method of polarization measurements was investigated. The methodology can be applied not only in the improvement of procedures for the treatment of museum collection items, but also in the field of processing archaeological finds or in teaching conservation-restoration students and other related fields of cultural heritage care.
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