Method, so called “glycin- nitrate process”, combined with high temperature solid state reaction, of preparation multi- component ceramic perovskite materials was studied. Two types of perovskite systems were prepared by this method. Firs one, based on LaNiO3 doped by calcium and aluminium and second one, based on SmFeO3 doped by calcium and nickel or cobalt. This method made possible preparation of one phase perovskite or perovskites with few percent of nickel in form of oxide. In systems containing both nickel and calcium another phases rich in calcium and nickel appeared.

In the diploma thesis, an overview of the existing literature focused on the thermoplastic co-extrusion method was worked out and based on the findings, extrusion of the monolayer and homogenous bodies from ZrO2, Al2O3, ZTA a ATZ was studied. For thermoplastic extrusion the capillary rheometer was modified and the nozzle was designed and fabricated. Applying the co-extrusion method, homogenous ceramic rods and monolayer rods in structure core/layer: ZrO2/Al2O3, ZrO2/ATZ and ZTA/Al2O3 were fabricated. In monolayer rods, the interface quality and defects that originate during preparation were evaluated. Technological parameters and properties of homogenous rods were used to rate the structure and defects in monolayer rods. Monolayer rods ZrO2/ATZ and ZTA/Al2O3 with 2.5 mm diameter and 45 mm length (containing small defects) were prepared by thermoplastic co-extrusion.

The topic of the thesis is preparation of ferroelectric and dielectric composite materials, particularly the work deals with the preparation of barium strontium titanate. In the theoretical part the possibilities of BST synthesis and its processing are described. The experimental part deals with precipitation synthesis of barium strontium titanate. Prepared powders were characterized in terms of morphology and phase composition. Further, pressureless sintering and hot isostatic pressing (HIP) were used for preparation of dense ceramics. Pure BST powders, that were formed and sintered, were prepared by sol-gel precipitation synthesis. The highest density was reached by slow sintering cycle (slow increase of temperature and delay during sintering) and sintering by HIP.

This diploma thesis is devoted to the use of 3D reconstruction using EBSD method for microstructural analysis of silicon nitride ceramic material predetermined for the rolling-mill used in the wire production. Application of this method can be used for the grain structure reconstruction and basic microstructural parameters can be than extracted. The development of a suitable method for 3D reconstruction of the structure of the materials the main aim of this work. There are described the different steps begun by sample preparation from the investigated material trough the optimisation of analysis parameters up to the visualization of the grain structure. New type of sample geometry has been designed which leads to the better and faster observation of the microstructure of ceramic materials. This thesis also describes optimal reconstruction parameters such as the geometry of the assembly used in the microscope without mechanical movement of the sample or the influence of conductive coating prepared via in-situ sputtering of suitable metal, or adjustment of the electron and ion beams. Further are described two options of software which can be used for the final generation of 3D structure information and are assessed their advantages and disadvantages. The effect of the filter setting and other parameters and their influence on the resulting structural parameters are also evaluated.

My thesis is a presentation of Jika Laufen for the international exhibition Expo 2015 in Milan. The work consists of designing and installing sinks into the exposure so that they are in a uniform manner. I designed the concept of the well for several reasons: the bathroom is an intimate space where it should be emphasized emotion , atmosphere and feelings. It is a space where a person should relax. The second aspect is that the ceramic has an organic origin, came from the ground and through the fire becomes very durable and solid. A no less important is the third aspect, exist on the context. Expo is an international exhibition and therefore the presentation of this forest exposure does not represent a Czech company, but also a Czech environment, where you will find beautiful nature and sources of known rivers. My concept is based on emotion and contrast materials. Delicate white ceramics have planted in a sharp stone and dark green leafy moss, creating a contrast full voltage . The exhibition of this type should not be missed even modern technology. That is my proposal represented feeler drain, which is around the perimeter of the sink hidden under the edge so as not to disturb the perception of the whole.

Sintering is a one of the key step in a processing of bulk ceramic materials. New sintering methods were invented in the last years. These new sintering methods, according to their authors, can be used for obtaining finer final microstructure of ceramics only by modifying the heating schedule. This work is focused on an influence of the Two Step Sintering method on the final microstructure for oxide ceramics. Obtained experimental results have shown that the effectivity of the Two Step Sintering method is rising with crystallographic symmetry of used material. Thesis is also focused on a high-temperature dilatometry and concept of the Master Sintering Curve. This concept was used for calculation of the activation energy of sintering and finding different sintering mechanisms acting in the intermediate and final stage of sintering. Activation energy of sintering was compared with activation energy of grain growth with target to find the kinetic window. Kinetic window can allow a sintering without a grain growth. Master Sintering Curve method was also used in a pressure assisted unconventional sintering technique Spark Plasma Sintering. Master Sintering Curve applied to a Spark Plasma Sintering technique reveals and quantified different sintering mechanisms acting in Spark Plasma Sintering. These findings led to preparation of transparent tetragonal ZrO2.

The thesis deals with electron beam micromachining of nonmetallic materials like glass, ceramics and plastics. A brief description of the device on which the experiments were carried out is included; the author has participated on its development. Main topic is experimental study of influence of main electron beam parameters on results of machining. Examined parameters include accelerating voltage, beam current, focusing and speed of machining. Influence of beam deflection is analyzed. Method of sequential machining by repeated passes of the electron beam is presented. Main examined materials are quartz glass, alumina and selected plastics. The usefulness of the technology is shown by several practical applications.

The doctoral thesis is orientated to preparation of advanced ceramic materials by electrophoretic deposition (EPD). The vertical mode of EPD in constant current regime was used in this study. The morphology of prepared materials (image structural analysis), physical properties (EPD yields, relative density, roughness of deposit surface) and mechanical properties (hardness, fracture toughness, elastic module) were characterized on the prepared deposits from alumina (Al2O3), zirconia (ZrO2) or their composites. It was found that the surface charge of alumina or zirconia particles was opposite (inversion charge) in stabilized isopropanolic dispersions than in case of water dispersions. The model of alumina or zirconia particles “inverse” stabilization was proposed. This type of EPD was further studied in presence of different acidic stabilizers. The obtained results from the experimental work (-potential and electric conductivity of dispersions, EPD yields, relative density of deposits, roughness of deposit surface etc.) showed the monochloracetic acid as the optimal type of acidic stabilizer. The kinetic of EPD process from dispersions containing isopropanol, monochloracetic acid and Al2O3 or ZrO2 particles and its influence on the final properties of prepared deposits was studied. The new method of kinetic measurement was developed. Due to good knowledge of EPD kinetic the ceramic laminates (Al2O3/ZrO2) with optimized layer thickness were prepared. The internal stresses and their influence on crack trajectory in ceramic laminates contained 100-150 strongly bonded layers were studied. It was found that the dominant role of crack deflection played the internal compressive stresses, i.e. with increasing of amount of internal compressive stresses the crack deflection was also increased. This work brought a new knowledge in the area of non-aqueous ceramic dispersion stabilization and preparation of heterostructured ceramic materials.

Disertacijos tikslas – šiuo metu turimos medžiagos iš Rytų Lietuvos geležies amžiaus gyvenviečių įvertinimas gyvenviečių archeologijos kontekste. Dėl taip susiklosčiusių istorinių aplinkybių, Lietuvos archeologijos mokslas beveik nuo pat savo ištakų buvo orientuotas gana siaura kryptimi – būtent į etnokultūrinius tyrinėjimus. Dėl šios priežasties didžiausias dėmesys nuolat buvo skiriamas laidojimo paminklams, o gyvenviečių medžiaga laikyta neinformatyvia. Pastaruoju metu, plečiantis archeologijos mokslo interesams, vis daugiau dėmesio skiriama socialiniams, ekonominiams, ideologiniams klausimams, kurių analizė be gyvenviečių medžiagos jau neįmanoma. Tačiau kadangi dauguma gyvenviečių kasinėjimų vykdyta keliant kitus tikslus, kuriems įgyvendinti taikyta kitokia metodika, šios medžiagos panaudojimas yra gana komplikuotas. Turimais duomenimis ne visada galima pasitikėti, jie reikalauja naujos interpretacijos. Disertacijoje daugiausiai dėmesio skiriama metodologiniams gyvenviečių tyrinėjimų ir medžiagos interpretavimo aspektams. Suformuluotas prie Lietuvos geležies amžiaus specifikos pritaikytas gyvenviečių archeologijos modelis, jis derinamas su turimais duomenimis iš Rytų Lietuvos gyvenviečių. Analizuojama, kokiems klausimams spręsti medžiagos turima daugiau, kuriems mažiau, kokie metodai gali padėti išspręsti aktualiausias problemas. Taip pat disertacijoje daug dėmesio skiriama gyvenviečių chronologijos problemoms, kurios iki šiol dar beveik neanalizuotos. Šiuo tikslu... [toliau žr. visą tekstą] / The main goal of this dissertation is the evaluation of the current material from the Iron Age eastern Lithuanian settlements in the context of the settlement archaeology. Historically developed circumstances determined that Lithuanian archaeology nearly from its origins has been oriented mainly towards ethnocultural research. Consequently the material from the burial monuments has been under the greatest consideration, settlement excavations were considered less informative. As the goals of archaeological research are broadening in Lithuania recently, social, economic and ideological aspects of culture are becoming more relevant. Settlement material is essential for the analysis of these subjects. However, as the majority of the settlement excavations were implemented under the different goals with different methods, the employment of their data is complicated. The data is not fully reliable, it requires reconsideration. Methodological aspects of settlement excavation and interpretation of its data are widely analysed in this dissertation. The model of settlement archaeology fitted to the properties of Lithuanian Iron Age sites is introduced here. Data from the Eastern Lithuanian settlements are treated in the context of this model. Problems of the chronology of settlements are under consideration here as well. Pottery from the Eastern Lithuanian settlements was revised for this purpose. The chronological scale with the intervals of 1-3 centuries has been constructed.

The main goal of this dissertation is the evaluation of the current material from the Iron Age eastern Lithuanian settlements in the context of the settlement archaeology. Historically developed circumstances determined that Lithuanian archaeology nearly from its origins has been oriented mainly towards ethnocultural research. Consequently the material from the burial monuments has been under the greatest consideration, settlement excavations were considered less informative. As the goals of archaeological research are broadening in Lithuania recently, social, economic and ideological aspects of culture are becoming more relevant. Settlement material is essential for the analysis of these subjects. However, as the majority of the settlement excavations were implemented under the different goals with different methods, the employment of their data is complicated. The data is not fully reliable, it requires reconsideration. Methodological aspects of settlement excavation and interpretation of its data are widely analysed in this dissertation. The model of settlement archaeology fitted to the properties of Lithuanian Iron Age sites is introduced here. Data from the Eastern Lithuanian settlements are treated in the context of this model. Problems of the chronology of settlements are under consideration here as well. Pottery from the Eastern Lithuanian settlements was revised for this purpose. The chronological scale with the intervals of 1-3 centuries has been constructed. / Disertacijos tikslas – šiuo metu turimos medžiagos iš Rytų Lietuvos geležies amžiaus gyvenviečių įvertinimas gyvenviečių archeologijos kontekste. Dėl taip susiklosčiusių istorinių aplinkybių, Lietuvos archeologijos mokslas beveik nuo pat savo ištakų buvo orientuotas gana siaura kryptimi – būtent į etnokultūrinius tyrinėjimus. Dėl šios priežasties didžiausias dėmesys nuolat buvo skiriamas laidojimo paminklams, o gyvenviečių medžiaga laikyta neinformatyvia. Pastaruoju metu, plečiantis archeologijos mokslo interesams, vis daugiau dėmesio skiriama socialiniams, ekonominiams, ideologiniams klausimams, kurių analizė be gyvenviečių medžiagos jau neįmanoma. Tačiau kadangi dauguma gyvenviečių kasinėjimų vykdyta keliant kitus tikslus, kuriems įgyvendinti taikyta kitokia metodika, šios medžiagos panaudojimas yra gana komplikuotas. Turimais duomenimis ne visada galima pasitikėti, jie reikalauja naujos interpretacijos. Disertacijoje daugiausiai dėmesio skiriama metodologiniams gyvenviečių tyrinėjimų ir medžiagos interpretavimo aspektams. Suformuluotas prie Lietuvos geležies amžiaus specifikos pritaikytas gyvenviečių archeologijos modelis, jis derinamas su turimais duomenimis iš Rytų Lietuvos gyvenviečių. Analizuojama, kokiems klausimams spręsti medžiagos turima daugiau, kuriems mažiau, kokie metodai gali padėti išspręsti aktualiausias problemas. Taip pat disertacijoje daug dėmesio skiriama gyvenviečių chronologijos problemoms, kurios iki šiol dar beveik neanalizuotos. Šiuo tikslu... [toliau žr. visą tekstą]