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Two-step sintering of advanced ceramic materials with various crystal structures
Žalud, Pavel ; Trunec, Martin (referee) ; Maca, Karel (advisor)
The influence of Two-Step Sintering (TSS) process on the final microstructure of oxide ceramics materials with two different crystal structures was studied. Tetragonal zirconia (stabilized with 3mol%Y2O3, particle size 90nm and 140nm ) and cubic zirconia (8mol%Y2O3, 70nm) powders were cold isostatically pressed and pressure less sintered with different heating schedules. The microstructures achieved with TSS method were compared with microstructures achieved with conventional Single-Step Sintering schedule (SSS). The results showed that the efficiency of the TSS of these oxide ceramics was more dependent on their crystal structure than on their particle size and green body microstructure. The method of TSS brought only negligible improvement of the microstructure of tetragonal zirconia ceramics. On the other hand, TSS was successful in the sintering of cubic zirconia ceramics; it led to a decrease in grain size by a factor of 2.
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The influence of sintering schedule on microstructure of advanced ceramic materials with cubic structure
Ecler, Matěj ; Pouchlý, Václav (referee) ; Maca, Karel (advisor)
This bachelor thesis deals with the study of the influence of heating schedule on the microstructure of advanced ceramic materials. Relative densities and grain sizes obtained by Single-Step Sintering and Two-Step Sintering were compared. Examined ceramic materials were CeO2, Y2O3 and spinel Al2O3MgO with cubic structure, and TiO2 with tetragonal structure. Only samples of Al2O3MgO and TiO2 achieved relative densities higher than 98%. For those two materials the microstructure was evaluated. The results did not confirm the influence of crystalline lattice symmetry on eciency of Two-Step Sintering.
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The influence of sintering schedule on microstructure of advanced ceramic materials with cubic structure
Ecler, Matěj ; Pouchlý, Václav (referee) ; Maca, Karel (advisor)
This bachelor thesis deals with the study of the influence of heating schedule on the microstructure of advanced ceramic materials. Relative densities and grain sizes obtained by Single-Step Sintering and Two-Step Sintering were compared. Examined ceramic materials were CeO2, Y2O3 and spinel Al2O3MgO with cubic structure, and TiO2 with tetragonal structure. Only samples of Al2O3MgO and TiO2 achieved relative densities higher than 98%. For those two materials the microstructure was evaluated. The results did not confirm the influence of crystalline lattice symmetry on eciency of Two-Step Sintering.
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Two-step sintering of advanced ceramic materials with various crystal structures
Žalud, Pavel ; Trunec, Martin (referee) ; Maca, Karel (advisor)
The influence of Two-Step Sintering (TSS) process on the final microstructure of oxide ceramics materials with two different crystal structures was studied. Tetragonal zirconia (stabilized with 3mol%Y2O3, particle size 90nm and 140nm ) and cubic zirconia (8mol%Y2O3, 70nm) powders were cold isostatically pressed and pressure less sintered with different heating schedules. The microstructures achieved with TSS method were compared with microstructures achieved with conventional Single-Step Sintering schedule (SSS). The results showed that the efficiency of the TSS of these oxide ceramics was more dependent on their crystal structure than on their particle size and green body microstructure. The method of TSS brought only negligible improvement of the microstructure of tetragonal zirconia ceramics. On the other hand, TSS was successful in the sintering of cubic zirconia ceramics; it led to a decrease in grain size by a factor of 2.
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