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Influence of alloying elements on the solubility of titanium in magnesium alloys
Matocha, Martin ; Buchtík, Martin (referee) ; Březina, Matěj (advisor)
This bachelor's thesis examines the influence of alloying elements on the solubility of titanium in magnesium alloys. In the theoretical part, a literature review was conducted on the topics of the creation, composition, processing, and brief analysis possibilities of magnesium alloys, with an emphasis on the potential for alloying magnesium alloys with titanium. The experimental part focused on the preparation of systems with various compositions to achieve the integration of titanium into the magnesium alloy. After preparation of the samples of the given systems, their analysis was performed using SEM/EDS and XRD. Based on the ongoing results of the samples analysis, efforts were made to optimize the holding time of the samples of the given system at a temperature of 905°C. It was found that during the stabilization of the modification of titanium, it is possible to achieve mixing of titanium, zinc, and magnesium. The condition for the formation of the modification of titanium is the highest possible temperature allowed by the system. However, the temperature must exceed at least 881°C. The stability of the modification of titanium is also supported by the absence of alloying elements that promote the stability of the modification of titanium. The mixture of elements in the aforementioned system has not yet been described in the scientific literature.
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Magnetic transformation of metastable fcc Fe/Cu(100) films by focused ion beam
Gloss, Jonáš ; Cháb, Vladimír (referee) ; Urbánek, Michal (advisor)
Metastable paramagnetic face-centered cubic (fcc) Fe thin films deposited on a Cu(100) single-crystal are good candidates for focused ion-beam magnetic patterning, due to their structural and magnetic phase transformation to ferromagnetic body-centered cubic (bcc) Fe upon ion-beam irradiation. However, pure fcc Fe films undergo spontaneous transformation when their thickness exceeds 10 ML. This limit can be extended to approximately 22 ML by deposition of Fe at increased CO background pressures. We show that much thicker films can be grown by alloying with Ni, that stabilizes the fcc phase. The amount of Ni necessary to stabilize non-magnetic, metastable fcc Fe films in dependence on the residual background pressure during the deposition is determined and a phase diagram revealing the metastable region is presented. It is also shown that the stabilizing effect of CO can be removed by artificial O saturation of the surface and thus the Ni-stabilized films can be grown also in systems with lower vacuum. Finally, we present fabrication of micro- and nanostructures in 44 ML thick films of Fe alloyed with Ni on Cu(100) by focused ion beam.
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Manufacturing, use and properties of duplex austenitic-ferritic steels
Klapetek, Václav ; Blažík, Petr (referee) ; Myška, Martin (advisor)
This bachelor thesis focuses on stainless duplex austenitic-feritic steels. The first chapter is focused on mechanical and technological properties, microstructure and chemical proposition with its impact on corrosion resistance, following the introduction to the issue. Intermetallic phases and their effect on properties are also described. Second chapter deals with their usage in several industry spheres, such as petrochemical industry, paper-producing, transport and storage of chemicals etc.
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Manufacturing, use and properties of duplex austenitic-ferritic steels
Klapetek, Václav ; Blažík, Petr (referee) ; Myška, Martin (advisor)
This bachelor thesis focuses on stainless duplex austenitic-feritic steels. The first chapter is focused on mechanical and technological properties, microstructure and chemical proposition with its impact on corrosion resistance, following the introduction to the issue. Intermetallic phases and their effect on properties are also described. Second chapter deals with their usage in several industry spheres, such as petrochemical industry, paper-producing, transport and storage of chemicals etc.
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Magnetic transformation of metastable fcc Fe/Cu(100) films by focused ion beam
Gloss, Jonáš ; Cháb, Vladimír (referee) ; Urbánek, Michal (advisor)
Metastable paramagnetic face-centered cubic (fcc) Fe thin films deposited on a Cu(100) single-crystal are good candidates for focused ion-beam magnetic patterning, due to their structural and magnetic phase transformation to ferromagnetic body-centered cubic (bcc) Fe upon ion-beam irradiation. However, pure fcc Fe films undergo spontaneous transformation when their thickness exceeds 10 ML. This limit can be extended to approximately 22 ML by deposition of Fe at increased CO background pressures. We show that much thicker films can be grown by alloying with Ni, that stabilizes the fcc phase. The amount of Ni necessary to stabilize non-magnetic, metastable fcc Fe films in dependence on the residual background pressure during the deposition is determined and a phase diagram revealing the metastable region is presented. It is also shown that the stabilizing effect of CO can be removed by artificial O saturation of the surface and thus the Ni-stabilized films can be grown also in systems with lower vacuum. Finally, we present fabrication of micro- and nanostructures in 44 ML thick films of Fe alloyed with Ni on Cu(100) by focused ion beam.
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