Ceramics Microstructure
Mostrando 1-12 de 56 artigos, teses e dissertações.
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1. Dolomite-zirconia reaction sintered bonded coarse magnesia ceramics: effect of the bonding proportion
Abstract Refractory ceramic materials were manufactured, mainly composed of magnesia grains (coarse and medium fraction) and CaZrO3/MgO as a binding phase produced from the reaction sintering between CaMg(CO3)2 (dolomite) and m-ZrO2 (monoclinic zirconia), which constituted the finer fraction. Different relationships between the proportion and the size of the
Cerâmica. Publicado em: 2021-06
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2. Influence of sintering parameters on the microstructure and mechanical properties of nanosized 3Y-TZP ceramics
Abstract The fracture toughness of 3Y-TZP ceramics obtained from a nanocrystalline powder with an optimized microstructure and highly transformable tetragonal grains was investigated. Samples of ZrO2-3 mol% Y2O3 were sintered at temperatures between 1250 and 1400 °C, with isothermal holding times of up to 16 h. Samples sintered at 1250 °C exhibited relativ
Cerâmica. Publicado em: 2021-03
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3. Caracterização e aproveitamento dos resíduos de argila e argilito provenientes da extração de gipsita no município de Araripina-Brasil como matérias-primas para cerâmica vermelha
Resumo O objetivo deste trabalho foi a caracterização e o aproveitamento dos resíduos de duas argilas (B e C, coletadas em diferentes camadas do capeamento) e argilito, gerados da extração da gipsita no município de Araripina, para a aplicação em cerâmica vermelha. Foram preparados os corpos de prova cerâmicos utilizando as argilas residuais com a
Cerâmica. Publicado em: 14/11/2019
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4. Evaluation of Solid Waste From H2S Removal Process in Natural Gas Treatment Incorporated Into Red Ceramic
Waste incorporation into clay ceramic is a worldwide accepted recycling procedure for environmentally friendly reuse of spent industrial materials. In the present work a clay ceramic from the city of Campos dos Goytacazes, Brazil, was, for the first time, investigated with different amounts, up to 10 wt%, of a solid waste generated from the “Sulfatreat”
Mat. Res.. Publicado em: 12/08/2019
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5. Microstructure and Weibull distribution of rupture strength of clay-talc ceramics
Resumo As propriedades mecânicas das cerâmicas de argila-talco contendo 0 a 10% em massa de talco sinterizadas a 1100 °C foram obtidas por medidas de flexão. Com o valor médio de resistência à flexão de 23,1 MPa, a amostra com 5% de talco (G5) foi a mais forte e apresentou o menor valor de poro interconectado (64%). A dispersão dos valores de resist
Cerâmica. Publicado em: 06/06/2019
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6. Microstructure, Mechanical Properties and in vitro Biological Behavior of Silicon Nitride Ceramics
The bioinert surface of silicon nitride ceramics led us to investigate the additions of SiO2, CaO and Al2O3 in order to aid the liquid phase sintering and improve the mechanical properties and biological behavior of the final materials. The sintered materials reached ca. 97% of theoretical density and total α→β-Si3N4 transformation. The samples had relat
Mat. Res.. Publicado em: 13/09/2018
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7. Production of Ba2AlNbO6 Ceramics and Study of their Stability in Crude Petroleum for the Conservation of Metallic Sensing Elements Used in Petroleum Extraction
In the present work niobium based complex cubic perovskite oxide Ba2AlNbO6 ceramics were produced, characterized and their stability in crude petroleum environment was studied for inert ceramic embedding used in petroleum extraction. Ba2AlNbO6 ceramic powder was prepared by means of thermo-mechanical processing. Structural characteristics of calcined materia
Mat. Res.. Publicado em: 26/07/2018
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8. Microstructure and Dielectric Behavior of Ytterbium Doped BaZr0.1Ti0.9O3 Ceramics
BaZr0.1Ti0.9O3 ceramics of perovskite structure are prepared by solid state reaction method with addition of x Yb2O3 (x= 0.0, 0.1, 0.3, 0.5 and 0.7 mol%), respectively, and their dielectric properties are investigated. Room temperature X-ray diffraction study suggested that the compositions have a single phase with a perovskite structure. A small decrease in
Mat. Res.. Publicado em: 10/10/2016
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9. Microstructure Evolution and Model Analysis of Al2O3/ZrO2 Hypoeutectic Ceramic During Rapid Solidification
Rapid solidification of the super high-temperature Al2O3/ZrO2 melt was studied by a novel method. The melt was prepared by explosion reaction using Al and Zr(NO3)4 as raw materials and then sprayed to Cu-plate. The heat transfer during the solidification process was analyzed by one-dimensional Finite Element Analysis. The cooling rate of the melt decreased w
Mat. Res.. Publicado em: 04/12/2015
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10. Properties of SiC Ceramics Sintered via Liquid Phase Using Al2O3 + Y2O3, Al2O3 + Yb2O3 and Al2O3 + Dy2O3 as Additives: a Comparative Study
Silicon carbide (SiC) ceramics show excellent performance at high temperatures. Due to the high covalence of Si-C bonds, these ceramics are produced successfully only via liquid phase sintering (LPS). In this work, SiC ceramics were sintered via LPS using eutectic mixtures of Al2O3+Y2O3, which served as a standard for comparison, Al2O3+Yb2O3 and Al2O3+Dy2O3.
Mat. Res.. Publicado em: 2015-06
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11. Evaluation of different methods of cooling-lubrication in cylindrical grinding of advanced ceramic dip
The current work presents a study of alternative methods of cooling-lubrication for the external plunge grinding of advanced ceramics using diamond wheels. These two alternative methods, which are intended to reduce cutting fluid expenses, are commonly referred to as the optimized cooling-lubrication method and minimal quantity of lubrication (MQL). The tech
Mat. Res.. Publicado em: 30/09/2014
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12. Effect of ZnO addition on the structure, microstructure and dielectric and piezoelectric properties of K0.5Na0.5NbO3 ceramics
Microstructure, structure and electrical and dielectric properties of ZnO-doped K0.5Na0.5NbO3 (KNN) ceramics were investigated. Powders were obtained by the conventional solid-state method. Samples doped with 0 to 1 mol% of ZnO were sintered at 1125 °C for 2 h. Through XRD spectra, the perovskite structure was detected, in addition to small peaks correspond
Mat. Res.. Publicado em: 29/04/2014