|
|
Suspension plasma spraying of sub-stoichiometric titania by hybrid water/argon stabilized plasma torch
Mušálek, Radek ; Ctibor, Pavel ; Medřický, Jan ; Tesař, Tomáš ; Kotlan, Jiří ; Lukáč, František
In this study, suspension plasma spraying of sub-stoichiometric titania was attempted using hybrid water/argon stabilized plasma torch (WSP-H). Porous coatings with fine cauliflower-like columnar microstructure were successfully deposited in two separate experiments with different power levels of the plasma torch. In both cases, high solid-load content (40 wt. %) of the water-based suspension resulted in considerable coating thickness increase per deposition cycle. Coating annealing and partial remelting of the surface asperities were also achieved by additional pass of plasma torch in front of the coating surface. According to X-ray diffraction, all coatings consisted dominantly of rutile phase. Detailed microscopic observation of the as-sprayed and annealed deposits showed that the local coloration of the coating (ranging from dark blue to beige) was driven by the local overheating of the rough coating surface which could also promote the oxygen intake. Moreover, sample annealing was also observed to increase the sample reflectivity as observed by UV-VIS-NIR scanning spectrophotometry
|
|
|
Deposition of Titania from Solution by Hybrid Water-Stabilized Plasma Torch
Mušálek, Radek ; Medřický, Jan ; Tesař, Tomáš ; Kotlan, Jiří ; Lukáč, František
Thermal spraying with liquid feedstock presents a novel route for deposition of functional coatings. In this study, possibility of preparation of titania coatings from solution by hybrid water stabilized plasma torch is presented. Coatings were prepared from solution of titanium isopropoxide Ti[OCH(CH3)2]4 in anhydrous ethanol. Fragmentation of feedstock stream in the plasma jet was monitored by shadowgraphy. Deposition was carried out on steel samples mounted to the cooled rotating carousel. Cross-sectional images from SEM microscope showed successful formation of the deposit with dual morphology consisting of fine feather-like features combined with bigger droplets. X-ray diffraction revealed formation of nanometric rutile crystallites.
|
|
| |
|
| |
|
|
surface finish for the container CASTOR
Tomek, Jan ; Kubíček, Jaroslav (referee) ; Žák, Ladislav (advisor)
Master’s thesis deals with the problems of the inner surface finish design for the CASTOR container. In the theoretical part are analyzed properties of metallic surfaces with their defects and various options of surface finishes for increased protection. The practical part of the thesis is focused on the design of appropriate technologies for specific requirements of the surface finish for the CASTOR container, creating test samples and their evaluation.
|
|
|
Optimalization of arc spraying parameters
Šildberger, Radek ; Filipenský, Jan (referee) ; Kubíček, Jaroslav (advisor)
The project elaborated as a part of engineering studies branch M2307: Engineering Technology, Specialization 02: Forming and Welding Technology deals with the optimization of arc spraying parameters for TAFA 9935 facility.The theoretical part presents the principle of arc spraying, the description of the technological process and the types of additional materials. The practical part proposes the diffrent possibilities of TAFA 9935 arc spraying facility and the suitable additional materials. Several samples with diffrent parameters of spraying were created in order to test and analyse the coating quality.
|
|
|
Application of plasma arc in technical practice
Bednář, Šimon ; Kubíček, Jaroslav (referee) ; Daněk, Ladislav (advisor)
The first part of the thesis is devoted to research of technology which use plasma arc, as cutting, thermal spraying, surface heat treating and welding, the great emphasis is putted on the technology of welding. Second part of it is devoted to assessment of welds/joints which are made by TIG method and by PLASMA. At the welds/joints is assessed the total amount of heat input and the course of hardness in the cross section. At the welds/joints that were made by PLASMA was determined percent of dilution.
|
|
|
Surface Characteristics and Materials of Internal Combustion Engines Piston Liners
Zloch, Jan ; Raffai, Peter (referee) ; Maršálek, Ondřej (advisor)
This work is professional research and addresses the issues of working surfaces of cylinders of internal combustion engines. It describes the technologies and concepts that are applied in the production of internal combustion engines currently. The characteristics of each of these technologies provides a description of the production process, finishing and the most common applications. Furthermore, the properties, structure, and achieved surface roughness created by these technologies are available.
|
|
|
Surface treatments of parts internal combustion engines
Toman, Josef ; Novotný, Pavel (referee) ; Maršálek, Ondřej (advisor)
This bachelor thesis is a professional research dedicated to the most frequently used surface treatments, applied to the stressed parts of internal combustion engines. The thesis also refers to surface treatments classification, benefits for the automotive industry and reasons for their development. Further it focuses on definitions of the technologies used, characteristics of processes and coatings, finishing operations after surface treatments and application of these treatments on the parts of internal combustion engines.
|
|
|
Repair of machinery
Teplý, Miroslav ; Kovář, Petr (referee) ; Kubíček, Jaroslav (advisor)
Theme of this Bachelor´s thesis deal with problems of repair of machinery - repair the shaft. The thesis is divided into two parts. The first part deals with the possibility of using thermal spraying for the renovation of the shaft surface at the point of contact with the shaft seal ring. The second part deals with the use of epoxy putty for the renovation of the shaft surface at the imposition of a bearing.
|
guest ::
