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Tridymite

About: Tridymite is a research topic. Over the lifetime, 840 publications have been published within this topic receiving 14831 citations.


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Journal ArticleDOI
TL;DR: In this paper, the in-situ synthesized mullite bonded SiC ceramics for solar thermal tower plant were prepared from silicon carbide (SiC), manufactured aluminum hydroxide (Al(OH)3) and Suzhou kaolin via semi-dry pressing and pressureless firing.
Abstract: The in-situ synthesized mullite bonded SiC ceramics for solar thermal tower plant were prepared from Silicon carbide (SiC), manufactured aluminum hydroxide (Al(OH)3) and Suzhou kaolin via semi-dry pressing and pressureless firing. The results indicate that sample B3 (designed mullite content 15 wt%) fired at 1 400 °C exhibited optimal performance with a bending strength of 97.41 MPa. Sample B3 can withstand 30-cycles thermal shock without cracking (wind cooling from 1 100 °C to room temperature), and the bending strength after thermal shock decreased by 17.92%. When the service temperature is 600 °C, the thermal diffusivity, specific heat capacity, thermal conductivity and heat capacity are 6.48×10−2 cm2·s−1, 0.69 kJ·kg−1· K−1, 9.62 W·m−1·K−1 and 977.76 kJ·kg−1, respectively. The XRD and SEM results show that SiC, mullite, α-quartz, and tridymite are connected closely, which gives the material a good bending strength. After 30-time thermal shock cycles, the structure of samples becomes loose. SiC grains are intersectingly arranged with rodshape mullite, exhibiting a favorable thermal shock resistance. The addition of Al(OH)3 and Suzhou kaolin can accelerate the synthesis of mullite, thus to reduce the firing temperature effectively. The volume effect of tridymite is relatively small, improving the thermal shock resistance of materials. A higher designed mullite content yields a lower loss rate of bending strength. The mullite content should not be more than 15 wt% or else the bending strength would be diminished.

8 citations

Journal ArticleDOI
TL;DR: In this paper, order models of oxygen positions in P63/mmc, C2221 and P212121 tridymites were given in applying geometrical and lattice dynamical calculations.
Abstract: Disorder models of oxygen positions in P63/ mmc, C2221 and P212121 tridymites were given in applying geometrical and lattice dynamical calculations. Sixmembered rings of rigid SiO4 units are all collapsed in these forms; with silicon atoms fixed, SiO4 units can take six different orientations in forming tridymite frameworks in both the P63/mmc and C2221 forms, and three orientations in the P212121 form. Atomic distances and angles obtained from the distance least-squares method are about equal for the three forms: 〈Si-O〉 (mean Si-O) = 1.611 A, 〈O-O〉 = 2.629 A, and 〈Si-O-Si〉 = 147°. Domain formation models are given for the three forms. The tridymite framework structures may possibly undergo lattice vibrations with low frequencies in two kinds of pair-wise rotational modes of SiO4 units joined by the apical oxygen atoms, at the Γ-point: one is around 〈100〉 (or 〈210〉 for the hexagonal case), and the other is around 〈010〉. As temperature approaches the hexagonal-orthorhombic transition from below, the rotational mode around 〈100〉 remarkably softens at the Γ-point. The behavior of the atoms at the hexagonal-orthorhombic transition is explained in terms of a coupled softening of the two rotational modes of neighboring local domains in different orientations.

8 citations

Patent
31 Jul 2007
TL;DR: In this paper, a piece is made by sintering a nanoparticle/ceramic mixture in air or under inert gas at temperatures of between 900° C and 1250° C.
Abstract: The invention relates to a piece comprised in part or in full of a pigmented ceramic in which the pigment is comprised of nanoparticles based on a metal from column IB of the periodic table of the elements or of an alkaline metal, or an alloy of both, coated with a layer of silica, the silica being crystalline silica, particularly cristobalite or tridymite. The ceramic is preferably zirconia or alumina. The nanoparticle silica is crystallized, for example, by a thermal treatment in air or under inert gas at temperatures of between 900° C. and 1400° C. The piece is made by sintering a nanoparticle/ceramic mixture in air or under inert gas at temperatures of between 900° C. and 1250° C.

8 citations

Journal ArticleDOI
TL;DR: In this article, the thermoluminescence of BaAl2O4 prepared by solution-combustion is reported, which is a stuffed tridymite used as a long-lasting phosphor.

8 citations

Book ChapterDOI
01 Jan 2016
TL;DR: A combined quantitative microanalysis technique including electron probe X-ray microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been developed to accurately characterize the equilibrated system for both major and minor elements.
Abstract: Laboratory studies have been carried out to determine the slag/matte/metal/tridymite four condensed-phase equilibria in the “Cu-Fe-Si-S-O” system and the minor element distributions between the equilibrated phases at 1200°C. A combined quantitative microanalysis technique including electron probe X-ray microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been developed to accurately characterize the equilibrated system for both major and minor elements. Analysis precision, estimated accuracy and current limitations are discussed. The resulting elemental distributions are plotted against matte grade and compared to FactSage predictions. It was found that the experimental results for major elements are in good agreement with FactSage predictions. The simultaneous distributions of Ag and Au between slag, matte and metal phases are reported for the first time.

8 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202315
202231
202125
202027
201920
201826