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Tailoring of physical properties of ceramic surface by the metallic layer deposition
Dvorský, Vojtěch ; Kachlík,, Martin (referee) ; Salamon, David (advisor)
The master thesis focuses on the preparation of nickel coating on ceramic (Al2O3) substrate. The deposition of nickel was carried out by the electroless plating method in bath at various kinetic conditions. An impact of varied size, shape and roughness on the quality of the coated surface was investigated. The main goal was to find optimized conditions of the plating process of the thin metal coatings. Prepared nickel coatings were analysed by SEM, EDX analysis, mechanical profilometry and the plating bath was analysed by UV-VIS spectrophotometry. The continuous nickel coatings were achieved by modifying the deposition process, and the kinetic mechanism of experimental conditions was described.
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Bulk materials from oxidized powder feedstock
Luptáková, Diana ; Molliková, Eva (referee) ; Jan, Vít (advisor)
In this thesis, methods of effective aluminium powder oxidation are evaluated, such as oxidation at higher temperatures in atmosphere, anodic oxidation and oxidation during high-energy ball milling. It describes following treatment and methods creating volume sammples in such way, where ductile properties are preserved, but the process of hardening by aluminium oxide occurs.
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Elimination of oxide rising during aluminum alloys welding
Vagunda, Pavel ; Kocich, Radim (referee) ; Sigmund, Marian (advisor)
This diploma thesis deals with the search of reason causing production of oxides in the welded joint, which have an impact on defects formation. The objective was to identify the areas in the technological process that can have the biggest impact on the oxides generation. The following areas of the technology process were selected: the length of storage time, the influence of the welder and the participation of the arc cleaning effect. The simulation imitating these effects was processed on Y and HY type welds with incomplete penetration. Subsequently, macroscopic inspection was provided to supply the most data used for evaluation. Defects in the root of the weld, caused by the oxides formation, appeared in the majority of the samples. From the evaluation was concluded, that the highest elimination is achieved by a significantly increased cleaning effect of the arc. Other influences didn‘t prove significant difference. The results were followed by an evaluation and solution proposal. The best solution seems to be adjusting the location of the weld on the blank, so that the weld root is fully penetrated. As a result, the welded joint isn‘t subject to the negative effects associated with oxides.
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Doped ceramic substrates for plasma aplications
Hliničan, Jan ; Šťastná, Eva (referee) ; Šťastný, Přemysl (advisor)
This bachelor thesis summarizes findings on subject: Doped ceramic substrates for plasma aplications. The thesis is divided into two parts. The first part is a literary research focused on topic: production of thin ceramic tapes by tape casting and their use. The second part is experimental. It deals with the preparation of alumina tapes doped with magnesium spinel (MgAl2O4) in different amounts. Phase composition and microstructure will be evaluated on prepared structures. The prepared samples will be used for the production of electrodes for atmospheric plasma discharge.
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Application of 3D printing for prepartion of advanced ceramic materials
Klusáček, Martin ; Kachlík, Martin (referee) ; Salamon, David (advisor)
In this bachelor thesis there are summarized main 3D printing methods of advanced ceramics. They are compared and their advantages and disadvantages are mentioned. In experimental part of this thesis two different ceramic suspensions were prepared and used for automated silicon form casting and direct 3D printing with financially available 3D printer. The analysis of results was based on reproducibility of the method and sample relative density. The mass accuracy of 5,3 % was reached. It was found out, that the relative density of samples over 98 % can be achieved with accuracy of 1 %.
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Elimination of oxide rising during aluminum alloys welding
Vagunda, Pavel ; Kocich, Radim (referee) ; Sigmund, Marian (advisor)
This diploma thesis deals with the search of reason causing production of oxides in the welded joint, which have an impact on defects formation. The objective was to identify the areas in the technological process that can have the biggest impact on the oxides generation. The following areas of the technology process were selected: the length of storage time, the influence of the welder and the participation of the arc cleaning effect. The simulation imitating these effects was processed on Y and HY type welds with incomplete penetration. Subsequently, macroscopic inspection was provided to supply the most data used for evaluation. Defects in the root of the weld, caused by the oxides formation, appeared in the majority of the samples. From the evaluation was concluded, that the highest elimination is achieved by a significantly increased cleaning effect of the arc. Other influences didn‘t prove significant difference. The results were followed by an evaluation and solution proposal. The best solution seems to be adjusting the location of the weld on the blank, so that the weld root is fully penetrated. As a result, the welded joint isn‘t subject to the negative effects associated with oxides.
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Bulk materials from oxidized powder feedstock
Luptáková, Diana ; Molliková, Eva (referee) ; Jan, Vít (advisor)
In this thesis, methods of effective aluminium powder oxidation are evaluated, such as oxidation at higher temperatures in atmosphere, anodic oxidation and oxidation during high-energy ball milling. It describes following treatment and methods creating volume sammples in such way, where ductile properties are preserved, but the process of hardening by aluminium oxide occurs.
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