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Materials Used for Cutting Tools for Metal Machining
Tomek, Lukáš ; Fiala, Zdeněk (referee) ; Kalivoda, Milan (advisor)
This thesis deals with cutting materials used for the production of inserts and tools for ma-chining. The aim of this thesis is to describe the various materials used in machining, their basic characteristics, composition and production. The work also includes a description of profiles of leading world producers of cutting tools. On the example of the designed shaft is made application of turning tools needed for its machining and short description of its production with a graphic demonstration. The final part is devoted to the evaluation of the turning in terms of used resources depending on the cost,productiontime and subsequent recycling of end-of-life instruments.
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Evolution of pores during sintering of advanced oxide ceramic materials
Spusta, Tomáš ; Kaštyl, Jaroslav (referee) ; Maca, Karel (advisor)
The goal of this bachelor’s thesis is to experimentally specify behaviour of pores in oxide ceramic materials (Al2O3, t-ZrO2, c-ZrO2), particularly to describe the transition from open to close porosity. Ceramics powders made by different producers and with different initial particle size (Al2O3 – AKP30, REYNOLDS, TAIMICRON; ZrO2 + 3 mol.% Y2O3 – TZ3Y, TZ3YSB; ZrO2 + 8 mol.% Y2O3 – TZ8Y, TZ8YSB) were used. Samples were pressed by cold isostatic pressing CIP at pressures of 100MPa and 300MPa, and pressureless sintered up to relative densities up to 88-96%. The obtained results show, that evolution is mainly affected by material, independently of size of initial particles neither by initial shaping pressure. Elimination of open pores occurs in cubic ZrO2 at 91-92 % of relative density, in tetragonal ZrO2 at 92-93 % of relative density and in Al2O3 at 94 % of relative density.
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Grain growth kinetics study of advanced oxide ceramic materials
Kazda, Adam ; Kachlík, Martin (referee) ; Pouchlý, Václav (advisor)
The goal of this work was to study the grain growth kinetics of five different materials: tetragonal ZrO2 (doped 3mol.% Y2O3 and particle size 80 nm), two cubic ZrO2 (doped 8 mol.% Y2O3 and particle sizes 80 and 140 nm) and two hexagonal Al2O3 (with particle sizes 100 and 240 nm). These ceramic powders were isostatically pressed and then they were isothermally sintered at 3 different temperatures for 1-60 hours. The biggest coarsening was discovered during temperature increase to sintering temperature. The dwelt at sintering temperature was not so important for coarsening. The activation energy of grain growth QG, growth exponent n and kinetic constant k0 were discovered for four materials. The activation energy of grain growth was 511±49 kJ/mol for tetragonal ZrO2, 645±84 kJ/mol for cubic ZrO2 a 428±75 kJ/mol a 606±24 kJ/mol for Al2O3. Possibility of kinetic window of sintering process for cubic ZrO2, tetragonal ZrO2, and Al2O3 with particle size 240 nm (doped MgO) were discovered by comparison of established activation energy of grain growth QG with activation energy of sintering QS from literature. Kinetic window of sintering process wasn’t found for high purity alumina with particle size 100 nm.
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Powder Metallurgy and Fundamentals of Sintering Process
Foltýnek, Jaroslav ; Pouchlý, Václav (referee) ; Čelko, Ladislav (advisor)
The bachelor thesis deals with the powder metallurgy and sintering process of metallic materials. The work is a recherche on this topic and includes a basic comprehensive insight into the entire production process consisting of the overview on the material powder processing techniques, introduction of the basic parameters of sintering process and mechanisms involved during sintering influencing the final compact product formation. The sintering process is in work divided into two basic categories, solid state and liquid-phase sintering.
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Binders on the base alumina cements and their properties
Morávková, Jitka ; Cupák, Petr (referee) ; Burianová, Klára (advisor)
The Bachelor Thesis describes chemical and mineralogical structure, as well as alumina cements manufacture and some of their physical and techno-logical properties. It takes accelerators or plasticizers induced changes by search method. An illustrative laboratory measurement of mixture with accel-erator and plasticizer is complementary to theoretical knowledge in fluidity, air permeability and strength of mixture with aluminium silicate cement binder.
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Catalytic behaviour of ceramic catalytic materials
Schlosser, Radek ; Cihlář, Jaroslav (referee) ; Cihlář, Jaroslav (advisor)
In this bachelor’s thesis the methods of preparation of ceramic perovskite-like membranes for heterogenous catalysis and reformation reactions of carbohydrates were studied. The syntetic La-Ca-Fe-Ti-O type and commercial La-Ca-Fe-Co-O type powders were used. The properties such as phase purity, specific surface area and morphology of used powders were determined. Technology of processing included powder uniaxial pressing, membrane sintering and polishing their surface. Conditions for uniaxial pressing were optimized. The dependence of grain size and amount of titanium was determined.
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Processing of Electroceramics from Nanopowders
Kachlík, Martin ; Trunec, Martin (referee) ; Maca, Karel (advisor)
Literature review of processing of bulk EuTiO3 ceramics was performed. Based on experiments performed the experimental conditions of solid-state reaction of Eu2O3 with Ti2O3, resp. TiO2 leading to single phase EuTiO3 were established. Balk EuTiO3 ceramics were prepared by means of cold isostatic pressing and sintering in reduction atmosphere. This ceramics is suitable for further evaluation of electromagnetic properties.
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Utilization of clays with low sintering temperature in brick technology
Sláma, Jakub ; Skotal, Zbyněk (referee) ; Sokolář, Radomír (advisor)
Bachelor thesis focuses on the use of the low sintering clays as additives in brickmaking. Their main use in the brick industry is mainly in the production of facing bricks and roof tiles. They are used for their very good sintering ability even at relatively lower firing temperatures. This feature is the most important for frost resistence of brick fragment. The theoretical part contains a summary and characteristic features of clays occurring in the Czech Republic and abroad. Further their requirements and laboratory testing of brick clay. In the practical part was conducted market research where are outlined available low sintering clays that may be proposed for use in brick fragment based on declared sintering. An experiment was performed in the next part of bachelor thesis to assess the effect of using low sintering clay in terms of particular brick factory in the Czech Republic (Tondach Šlapanice).
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THE INFLUENCE OF CONSOLIDATION PROCEDURE PARAMETERS ON COMPACTION OF AL POWDER
Lowe, T. C. ; Kunčická, L. ; Kocich, R. ; Davis, C. F. ; Hlaváč, L. ; Dvořák, Jiří
The influence of different consolidation procedures on compaction of Al powders was evaluated. Powder preparation procedures consisted of selection of particle size distribution, cold isostatic pressing (CIP), and vacuum sintering. Processing parameters investigated included the number of compression steps, compression pressure, and sintering temperature and time. Densities of the samples after compression and also after sintering were measured and compared. The overall oxygen content was analysed using by Energy Dispersive Spectroscopy. Phase composition was determined using X-ray. Microhardness measurements were performed to evaluate the degree of compaction. Double-step CIP at 200+300 MPa and subsequent sintering at 500°C for 60 min produced the best combination of properties from all the consolidation technologies of Al particles. Of the particle size ranges studies, those with diameters between 20 and 45 μm produced the best results. Aluminum oxide was present in the structure after all the processing treatments.
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Powder injection moulding of a ceramic part
Hausnerová, B. ; Marcaníková, L. ; Filip, Petr
The aim of the study is to optimize the production of alumina ceramic parts via Powder Injection Moulding (PIM) technology. As a case study fabric with main demand on surface-roughness tolerances has been selected with the potential of high production quantities for textile machines industry. The process is searched in terms of material tailoring, part design and dimensions, and processing conditions of injection moulding, debinding and sintering steps. Rheological, thermal and pressure-volume-temperature characteristics were measured in order to provide the reliable data for the simulation of injection moulding as well as thermal and thermogravimetric analyses have been carried out to attain non-porous final sintered products.
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