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Influence of low-temperature plasma on enhaced ceramic processing
Rolek, Ondřej ; Kachlík, Martin (referee) ; Pouchlý, Václav (advisor)
This masters’s thesis contains literary research about basic shaping methods of ceramic materials concerning the slip casting method. In addition, stabilization of ceramic slips, drying of ceramic green bodies and their subsequent sintering are described. This thesis also includes a description of plasma technology, including DCBD (Diffuse Coplanar Barrier Discharge) technology. In experimental part of this thesis the Al2O3 powder was treated with DCBD technology. From the prepared powder, the green body was prepared by the slip casting method, which was subsequently sintered by one-step and two-step sintering. The thesis describes the methods of preparation of ceramic samples and their evaluation. Evaluated experiments have shown that plasma technology has a positive effect on the treatment of ceramic powder Al2O3. Alumina ceramic samples of high relative density ( 99%) and low grain size (
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Preparation of ceramic-metal composites for ballistic protection
Hladík, Jakub ; Roleček, Jakub (referee) ; Salamon, David (advisor)
Cílem této práce je příprava keramicko-kovového kompozitu pro balistickou ochranu. Přičemž velká pozornost se klade na rozhraní obou materiálů. Práce popisuje jak vlastnosti používaných keramik a kovů, tak i aplikovatelné mechanické testy Kompozit na bázi oxidu hlinitého a hliníků byl experimentálně připraven metodou gravitačního lití / slinování hliníků, která vedla ke spojení s korundovými hexagony. K dosažení optimálního výsledku a co nejnižší teplotě lití bylo třeba vyzkoušet několik teplotních režimů. Připravené vzorky byly balisticky testovány na základě norem NIJ Standard- 0108.01 a NATO Standard STANAG 2280. Vlastnosti rozhraní byly ověřeny pomocí lomové analýzy vzorků, která zkoumala vzorky poškozené balistickým testováním. Za účelem zkoumání rozhraní byla připraveny speciální zkouška čtyřbodým ohybem. Dále bylo provedeno předběžné zkoumání mikrostruktury hliníku.
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Aluminium oxide ceramics microstructure modification for ballistic testing
Rolek, Ondřej ; Drdlík, Daniel (referee) ; Roleček, Jakub (advisor)
This bachelor thesis describes basic shaping methods of ceramic materials and drying processes of wet ceramics, with concern of slip casting method. The experimental part of this thesis presents the usage of slip casting method for preparation of Al2O3 ceramic plates, suitable for personal and vehicle ballistic protection. Tailoring of the slip casting plaster molds, with regard to the resulting properties of the Al2O3 ceramic body, in particular its relative density, is also described in this part. The influence of sintering temperature on final relative density of ceramic samples and on their microstructure especially their grain size is also shown in the practical. Bulk ceramic samples suitable for upcoming ballistic testing with low grain size (1,18 m) and high relative density exceeding 99 % were prepared from alumina.
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Preparation of ceramic-metal composites for ballistic protection
Hladík, Jakub ; Roleček, Jakub (referee) ; Salamon, David (advisor)
Cílem této práce je příprava keramicko-kovového kompozitu pro balistickou ochranu. Přičemž velká pozornost se klade na rozhraní obou materiálů. Práce popisuje jak vlastnosti používaných keramik a kovů, tak i aplikovatelné mechanické testy Kompozit na bázi oxidu hlinitého a hliníků byl experimentálně připraven metodou gravitačního lití / slinování hliníků, která vedla ke spojení s korundovými hexagony. K dosažení optimálního výsledku a co nejnižší teplotě lití bylo třeba vyzkoušet několik teplotních režimů. Připravené vzorky byly balisticky testovány na základě norem NIJ Standard- 0108.01 a NATO Standard STANAG 2280. Vlastnosti rozhraní byly ověřeny pomocí lomové analýzy vzorků, která zkoumala vzorky poškozené balistickým testováním. Za účelem zkoumání rozhraní byla připraveny speciální zkouška čtyřbodým ohybem. Dále bylo provedeno předběžné zkoumání mikrostruktury hliníku.
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Influence of low-temperature plasma on enhaced ceramic processing
Rolek, Ondřej ; Kachlík, Martin (referee) ; Pouchlý, Václav (advisor)
This masters’s thesis contains literary research about basic shaping methods of ceramic materials concerning the slip casting method. In addition, stabilization of ceramic slips, drying of ceramic green bodies and their subsequent sintering are described. This thesis also includes a description of plasma technology, including DCBD (Diffuse Coplanar Barrier Discharge) technology. In experimental part of this thesis the Al2O3 powder was treated with DCBD technology. From the prepared powder, the green body was prepared by the slip casting method, which was subsequently sintered by one-step and two-step sintering. The thesis describes the methods of preparation of ceramic samples and their evaluation. Evaluated experiments have shown that plasma technology has a positive effect on the treatment of ceramic powder Al2O3. Alumina ceramic samples of high relative density ( 99%) and low grain size (
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Aluminium oxide ceramics microstructure modification for ballistic testing
Rolek, Ondřej ; Drdlík, Daniel (referee) ; Roleček, Jakub (advisor)
This bachelor thesis describes basic shaping methods of ceramic materials and drying processes of wet ceramics, with concern of slip casting method. The experimental part of this thesis presents the usage of slip casting method for preparation of Al2O3 ceramic plates, suitable for personal and vehicle ballistic protection. Tailoring of the slip casting plaster molds, with regard to the resulting properties of the Al2O3 ceramic body, in particular its relative density, is also described in this part. The influence of sintering temperature on final relative density of ceramic samples and on their microstructure especially their grain size is also shown in the practical. Bulk ceramic samples suitable for upcoming ballistic testing with low grain size (1,18 m) and high relative density exceeding 99 % were prepared from alumina.
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Crack propagation in ceramics laminates with strongly bonded interfaces
Hadraba, Hynek ; Chlup, Zdeněk ; Maca, K. ; Bermejo, R.
Crack propagation through layered composites based on Al2O3 and ZrO2 was studied. The strongly bonded laminates with single-component layers and laminates with two-component layers were prepared via electrophoretic deposition and slip casting respectively. Laminates of different pre-defined thicknesses and composition contained different magnitudes of residual stress. Cracks, produced by an indentation technique, propagated towards layer interfaces deflected towards the interface in the compressed layers and away from the interface in the layers containing tension stress. Changes in the direction of crack propagation were described for the whole range of angles of incidence (0° - 90°). The biggest change in the crack propagation was observed, irrespective of the magnitude of residual stress in the layers.
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Crack propagation in strongly bonded Al2O3/ZrO2 laminates
Hadraba, Hynek ; Chlup, Zdeněk ; Maca, K. ; Bermejo, R.
Crack propagation through layered composites based on Al2O3 and ZrO2 was studied. The strongly bonded laminates with single-component layers (A/Z) and laminates with two-component (AtZ/AmZ) layers were prepared via electrophoretic deposition and slip casting respectively. Laminates of different pre-defined thicknesses and composition contained different magnitudes of residual stress. Cracks, produced by an indentation technique, propagated in direction to layer interfaces deflected towards the interface in the compressed layers and away from the interface in the layers containing tension stress. Changes in the direction of crack propagation for the whole range of angles of incidence (0° - 90°) were described. The biggest change in the crack propagation was observed for the angle of incidence 45° for A/Z systems and 32.5° for AtZ/AmZ systems and was ca. 15° and 20° respectively. The change in the crack propagation was independent on magnitude of residual stress in the layers.
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