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Processing and properties of lead free piezoceramic materials
Tásler, Jan ; Částková, Klára (referee) ; Maca, Karel (advisor)
This bachelor thesis deals with the study of lead free piezoceramic materials with comprehensive focus on the material called BCZT. The effect of different milling duration of the ceramic precursors and the effect of sintering temperature of the green body on the relative density and grain size of the final ceramics is studied on the prepared samples of this material with chemical composition of (Ba0,85Ca0,15)(Zr0,1Ti0,9)O3. Also, the effect of microstructure on the piezoelectric properties is examined. Both the milling duration and sintering temperature are key factors which influence the microstructure of ceramics. The effect of microstructure on the piezoelectric properties was confirmed mainly for piezoelectric coefficients d33 and kp.
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Design of tester of piezoelectric PVDF layers
Sijková, Simona ; Rubeš, Ondřej (referee) ; Hadaš, Zdeněk (advisor)
The diploma thesis deals with a design of a tester device, a selection and verification of a suitable method for comparing the piezoelectric properties of tested PVDF samples. In the introduction, a basic overview of the theory is important to understand the issue and the various branches of use of PVDF in the field of energy harvesting. The tester device includes a unimorph piezoelectric cantilever beam with tip mass, whose properties are described by three models: a model with N degrees of freedom reduced to one degree of freedom (NDOF), a single degree of freedom model (SDOF), both created in Matlab and a model for verifying results in FEM ANSYS Workbench program. The voltage time response and the voltage frequency response of the models is compared with each other. For two different PVDF samples, the voltage response to harmonic excitation is measured using a tester device, and the piezoelectric properties of one of them are determined using the NDOF and SDOF models.
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Physical and electrical properties of 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics
Král, Michael ; Nan, Bo (referee) ; Hughes, Hana (advisor)
Účelem této práce je příprava prášku a bezolovnaté keramiky se složením 0,5Ba(Zr0,2Ti0,8)O3-0,5(Ba0,7Ca0,3)TiO3 a následné měření jejích fyzikálních a elektrických vlastností. Práce obsahuje literární rešerši na téma piezokeramické materiály a jejich vlastnosti, společně s experimentální částí, která popisuje přípravu a měření vlastností vzorků. Přínosy práce jsou přesný popis výroby a měření vlastností, stanovení fyzikálních a elektrických vlastností této bezolovnaté piezoelektrické keramiky a návrhy na další vývoj. Nejlepší elektrické vlastnosti byly naměřeny na vzorcích slinovaných při teplotě 1425 °C a to d33 = 290.5 pC/N, průměrná velikost zrn 46.8 m a relativní hustota 93.9 %.
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Preparation of the lead-free piezoceramic by non-conventional sintering methods
Sršeň, Maroš ; Prajzler, Vladimír (referee) ; Pouchlý, Václav (advisor)
Ceramic materials that exhibit piezoelectric properties currently have a variety of uses in various industries, such as the automotive industry or information technology. Leading materials are currently the best ceramic piezoelectrics, but these materials show considerable toxicity. This has led to the need to find health-safe and environmentally friendly materials based on lead-free piezoelectric materials. Among these materials, KNN-based materials prove to be good candidates. However, their preparation has its own specifications, and therefore the use of conventional sintering methods may not lead to the desired results. It is for this reason that research into the preparation of these materials using unconventional sintering methods that use electric current for sintering has come to the fore in recent years. One of these methods is the Spark Plasma Sintering method, which has therefore been intensively researched in recent years. Within the experimental part of the work, ceramic bodies based on KNN were prepared. Sintering was performed by a conventional method using a laboratory oven, as well as by an unconventional Spark Plasma Sintering method, and the results were compared. Compacting ceramic bodies with high relative density were obtained by sintering by both methods. It has been shown that the Spark Plasma Sintering method can be used to prepare lead-free piezoelectric materials with a high relative density in a relatively short time. It has also been confirmed that the Spark Plasma sintering method has several advantages over conventional sintering methods, and that the ceramic bodies obtained have a higher relative density when sintered by this method.
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Preparation of the lead-free piezoceramic by non-conventional sintering methods
Sršeň, Maroš ; Prajzler, Vladimír (referee) ; Pouchlý, Václav (advisor)
Ceramic materials that exhibit piezoelectric properties currently have a variety of uses in various industries, such as the automotive industry or information technology. Leading materials are currently the best ceramic piezoelectrics, but these materials show considerable toxicity. This has led to the need to find health-safe and environmentally friendly materials based on lead-free piezoelectric materials. Among these materials, KNN-based materials prove to be good candidates. However, their preparation has its own specifications, and therefore the use of conventional sintering methods may not lead to the desired results. It is for this reason that research into the preparation of these materials using unconventional sintering methods that use electric current for sintering has come to the fore in recent years. One of these methods is the Spark Plasma Sintering method, which has therefore been intensively researched in recent years. Within the experimental part of the work, ceramic bodies based on KNN were prepared. Sintering was performed by a conventional method using a laboratory oven, as well as by an unconventional Spark Plasma Sintering method, and the results were compared. Compacting ceramic bodies with high relative density were obtained by sintering by both methods. It has been shown that the Spark Plasma Sintering method can be used to prepare lead-free piezoelectric materials with a high relative density in a relatively short time. It has also been confirmed that the Spark Plasma sintering method has several advantages over conventional sintering methods, and that the ceramic bodies obtained have a higher relative density when sintered by this method.
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Design of tester of piezoelectric PVDF layers
Sijková, Simona ; Rubeš, Ondřej (referee) ; Hadaš, Zdeněk (advisor)
The diploma thesis deals with a design of a tester device, a selection and verification of a suitable method for comparing the piezoelectric properties of tested PVDF samples. In the introduction, a basic overview of the theory is important to understand the issue and the various branches of use of PVDF in the field of energy harvesting. The tester device includes a unimorph piezoelectric cantilever beam with tip mass, whose properties are described by three models: a model with N degrees of freedom reduced to one degree of freedom (NDOF), a single degree of freedom model (SDOF), both created in Matlab and a model for verifying results in FEM ANSYS Workbench program. The voltage time response and the voltage frequency response of the models is compared with each other. For two different PVDF samples, the voltage response to harmonic excitation is measured using a tester device, and the piezoelectric properties of one of them are determined using the NDOF and SDOF models.
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Processing and properties of lead free piezoceramic materials
Tásler, Jan ; Částková, Klára (referee) ; Maca, Karel (advisor)
This bachelor thesis deals with the study of lead free piezoceramic materials with comprehensive focus on the material called BCZT. The effect of different milling duration of the ceramic precursors and the effect of sintering temperature of the green body on the relative density and grain size of the final ceramics is studied on the prepared samples of this material with chemical composition of (Ba0,85Ca0,15)(Zr0,1Ti0,9)O3. Also, the effect of microstructure on the piezoelectric properties is examined. Both the milling duration and sintering temperature are key factors which influence the microstructure of ceramics. The effect of microstructure on the piezoelectric properties was confirmed mainly for piezoelectric coefficients d33 and kp.
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Physical and electrical properties of 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics
Král, Michael ; Nan, Bo (referee) ; Hughes, Hana (advisor)
Účelem této práce je příprava prášku a bezolovnaté keramiky se složením 0,5Ba(Zr0,2Ti0,8)O3-0,5(Ba0,7Ca0,3)TiO3 a následné měření jejích fyzikálních a elektrických vlastností. Práce obsahuje literární rešerši na téma piezokeramické materiály a jejich vlastnosti, společně s experimentální částí, která popisuje přípravu a měření vlastností vzorků. Přínosy práce jsou přesný popis výroby a měření vlastností, stanovení fyzikálních a elektrických vlastností této bezolovnaté piezoelektrické keramiky a návrhy na další vývoj. Nejlepší elektrické vlastnosti byly naměřeny na vzorcích slinovaných při teplotě 1425 °C a to d33 = 290.5 pC/N, průměrná velikost zrn 46.8 m a relativní hustota 93.9 %.
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