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Showing 1 to 20 of 45 for “"mullite"”.
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Microstructure development in alkoxide-derived mullite and mullite/zirconia composites
Made available in DSpace on 2011-05-07T13:05:51Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9503362.pdf: 6061044 bytes, checksum: a80d4cfd87ff6cfa07c6e501b0ab11c4 (MD5) Previous issue date: 1994
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Thermal expansion of chemically modified mullite
… used extensively to form chemically-modified mullite solid solutions in an effort to lower their thermal expansion coefficients. TiO₂, B₂O₃, CrPO₄, P2O₅, Ga₂O₃, Cr2O₃, and WO₃ and the half-breed SiO₂ compounds AlPas, BPO₄, GaPO₄, BAsO₄, AIAsO₄, GaAsO₄, and GeO₂ were chosen as the modifiers. …
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Simulation of Microwave Heating of Mullite Rods
Microwave processing has been studied as an alternate heating technique over conventional heating for industrial applications. Some advantages include quicker and more uniform heating. Also, microwave energy offers the advantage of localized heating and smaller-sized equipment. Many ceramics, …
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Growth of Textured Mullite Fibers Using Polycrystalline Precursors
Mullite whiskers were prepared by HF leaching and templated into polycrystalline mullite fibers by extrusion. Textured growth of mullite fibers with elongated grains, aligned along the long-axis of the fibers, was achieved by heat treatment. Repeated heat treatment cycles of a whisker-templated …
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Kinetics and Pathways for Crystallization of Amorphous Mullite and YAG
Pseudotetragonal mullite gradually converted to equilibrium, orthorhombic, 3:2 mullite between 1000--1400°C. This was characterized by assimilation of the embedded, silica-rich inclusions and the elimination of internal strain. Additionally, recrystallization of numerous, small, strain- and …
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Microstructural development, phase stability, and toughening in mullite matrix composites
Mullite matrix composites with partially stabilized zirconia and/or SiC whiskers were fabricated by hot pressing of powders which had been prepared from Al, Si, Zr, and Mg (or Y) alkoxide precursors by a sol-gel process. A series of studies were conducted on microstructural evolution, oxidation …
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Thermal conductivity/diffusivity of SiC-Mullite and SiC-SiC composites
… diffusivity and/or thermal conductivity of SiC-Mullite and SiC-SiC, and to explain the observed behavior in terms of changes in temperature, microstructure, composition, and/or orientation. Materials used in the SiC-Mullite study consisted of single crystal SiC whiskers (prepared from rice hulls …
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MOFs functionalization of 3D printed mullite architectures: hierarchically porous systems for CO2 capture
L'abstract è presente nell'allegato / the abstract is in the attachment
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Processing, microstructure and mechanical properties of alumina platelet reinforced 3Y-TZP and mullite composites
Ceramic matrix composites consisting of mullite and 3Y-TZP containing alumina platelet reinforcements were fabricated by suspension processing and pressureless sintered. The effect of the matrix on the microstructural development in the presence of alumina platelets were characterized. A systematic …
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Ab initio calculations of mechanical, thermodynamic and electronic structure properties of mullite, Iota-alumina and boron carbide
… crystal structures of the other phases, called mullite, have partially occupied sites. Stoichiometric supercell models for the four mullite phases 3Al₂O₃ • 2SiO₂, 2Al₂O₃ • SiO₂ , 4Al₂O₃ • SiO₂ , 9Al₂O₃ • SiO₂ , and ι-Al₂O₃ (iota-alumina) are constructed starting from experimentally reported …
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Mullite Membrane Reference Electrode Evaluation and Application for Ni-Cr Corrosion Behavior in High Temperature Chloride Salts
… of Ni-Cr alloy corrosion in chloride salt. A mullite tube used as the membrane of a Ni(II)/Ni reference electrode in molten MgCl2-NaCl-KCl is studied. The performance of two different membrane thicknesses (1.325mm and 0.255mm) was studied in temperature ranges from 635oC to 835oC and data …
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The effect of the anion and cation of the catalyst on the catalytic mullitization of kaolinite
… and cation of various catalytic additives on the mullite development in a Georgia Kaolin. The sodium and potassium compounds investigated were found to be poor catalysts. The calcium compounds were very good catalysts while the lithium compounds ranged from poor to very good for lithium chloride. …
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Use of sol chemistry and fine grained precursors in the production of controlled microstructural polycrystalline continuous oxide fibres
Novel mullite fibres have been produced on a laboratory scale by pyrolysis of sol-gel spun precursors, having nanosized grains or discrete atomic dispersion, stabilised by in-situ precipitation of a minor phase addition of zirconia. A complex blend of chloride free precursors in aqueous media …
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Novel, inorganic composites using porous, alkali-activated, aluminosilicate binders
… with unidirectional continuous polycrystalline mullite fibers (Nextel™ 720) and single crystal mullite fibers, then the matrix was crystallized to form cubic pollucite. Single crystal mullite fibers were obtained by the internal crystallization method and show excellent creep resistance up to …
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The approach to equilibrium of mixtures of CaO, A1₂O₃, and SiO₂ heated to various temperatures
… when certain compositions of the anorthite-mullite-cristobalite and the anorthite-gehlenite-corundum compatibility triangles were fired to 1400° C. The effect on equilibrium of different raw materials used to form the compositions was also studied. Based on the results of the present …
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Durability testing of ceramic candle filters in pressurized-fluidized bed combustion environments
… amount of clay binder, a cordierite filter, a mullite candle filter and an aluminosilicate refractory concrete filter. Exposure testing conditions included a range of temperature from 700-850°C and a pressure ranging from 1.7-1.8 MPa. The HTHP tests included exposing the ceramic filter …
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Design of Sintered, Tough, Oxide Laminate and Fibrous Monolithic Composites
… and co-extrusion technique, respectively. Mullite (3Al 2O3·2SiO2), alumina (Al2O 3), 50 vol% alumina · 50 vol% YAG (yttrium aluminum garnet, Y 3Al5O12) in situ composite, 50 vol% alumina · 50 vol% mullite in situ composite, zirconia (ZrO 2), and nickel aluminate …
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Sodium sulfate corrosion of silicon carbide fiber-reinforced lithium aluminosilicate glass-ceramic matrix composites
… argon. A significant reduction in the amount of mullite in the matrices of all heat-treated samples was observed. Mullite dissolved into either the glassy phase or into the Beta- spodumene matrix. Lastly, the presence of distinct magnesium silicate crystalline phases in the salt-coated and …
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Fundamental studies on ionomer glasses
… glass was found to crystallize to apatite and mullite. Apatite is the mineral phase of bone and enamel and this may explain the excellent biocornpatability of glass ionomer cements. Glasses containing sodium and phosphate ions have also been produced. The sodium containing glasses were all …
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