Bibliographies thématiques / Lithia silica based ceramics

Littérature scientifique sur le sujet « Lithia silica based ceramics »

Auteur : Grafiati
Publié le 10 mars 2023

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Sommaire

Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Lithia silica based ceramics ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Articles de revues sur le sujet "Lithia silica based ceramics"

1

Le Bars, Nathalie, et L. C. Klein. « Lithia distribution in infiltrated silica gels ». Journal of Non-Crystalline Solids 122, no 3 (août 1990) : 291–97. http://dx.doi.org/10.1016/0022-3093(90)90994-w.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
2

Daguano, Juliana K. M. B., Mariana T. B. Milesi, Andrea C. D. Rodas, Aline F. Weber, Jorge E. S. Sarkis, Marcos A. Hortellani et Edgar D. Zanotto. « In vitro biocompatibility of new bioactive lithia-silica glass-ceramics ». Materials Science and Engineering : C 94 (janvier 2019) : 117–25. http://dx.doi.org/10.1016/j.msec.2018.09.006.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
3

Tucker, Dennis S. « Dynamic Fatigue of a Lithia-Alumina-Silica Glass-Ceramic ». Journal of the American Ceramic Society 73, no 8 (août 1990) : 2528–30. http://dx.doi.org/10.1111/j.1151-2916.1990.tb07627.x.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
4

DELLABONA, A. « Fracture behavior of lithia disilicate- and leucite-based ceramics ». Dental Materials 20, no 10 (décembre 2004) : 956–62. http://dx.doi.org/10.1016/j.dental.2004.02.004.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
5

Anusavice, Kenneth J., et Nai-Zheng Zhang. « Chemical durability of Dicor and lithia-based glass-ceramics ». Dental Materials 13, no 1 (janvier 1997) : 13–19. http://dx.doi.org/10.1016/s0109-5641(97)80003-6.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
6

RAY, CHANDRA S., WENHAI HUANG et DELBERT E. DAY. « Crystallization Kinetics of Lithia-Silica Glasses : Effect of Composition and Nucleating Agent ». Journal of the American Ceramic Society 70, no 8 (août 1987) : 599–603. http://dx.doi.org/10.1111/j.1151-2916.1987.tb05714.x.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Homeny, Joseph, Janet R. VanValzah et Mark A. Kelly. « Interfacial Characterization of Silicon Carbide Fiber/Lithia-Alumina-Silica Glass Matrix Composites ». Journal of the American Ceramic Society 73, no 7 (juillet 1990) : 2054–59. http://dx.doi.org/10.1111/j.1151-2916.1990.tb05266.x.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
8

Soares, R. S., R. C. C. Monteiro, M. M. R. A. Lima et R. J. C. Silva. « Crystallization of lithium disilicate-based multicomponent glasses – effect of silica/lithia ratio ». Ceramics International 41, no 1 (janvier 2015) : 317–24. http://dx.doi.org/10.1016/j.ceramint.2014.08.074.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
9

Fabian-Fonzar, R., C. Goracci, M. Carrabba, M. Ferrari et A. Vichi. « Acid concentration and etching time efficacy on lithia-based glass ceramics ». Dental Materials 32 (2016) : e91-e92. http://dx.doi.org/10.1016/j.dental.2016.08.191.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
10

Coon, Dennis N. « Effect of Silicon Carbide Additions on the Crystallization Behavior of a Magnesia-Lithia-Alumina-Silica Glass ». Journal of the American Ceramic Society 72, no 7 (juillet 1989) : 1270–73. http://dx.doi.org/10.1111/j.1151-2916.1989.tb09725.x.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
Plus de sources

Thèses sur le sujet "Lithia silica based ceramics"

1

Forberger, Virag Nicole. « Influence of the type of post and core on in vitro marginal continuity, fracture resistance, and fracture mode of lithia disilicate-based all-ceramic crowns / ». [S.l.] : [s.n.], 2009. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000278509.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
2

Cao, Jing. « Creation and orientation of nano-crystals by femtosecond laser light for controlling optical non-linear response in silica-based glasses ». Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS055/document.

Texte intégral
Résumé :
En raison d’un désordre aléatoire à longue distance, un verre présente une symétrie d'inversion telle que la génération de seconde harmonique (GSH) est interdite. Cependant, par irradiation avec un laser femtoseconde (fs) très focalisé, il est possible de précipiter des cristaux optiquement non linéaires, et de rompre la symétrie d'inversion et donc d'induire une GSH. De plus, ceci peut être réalisé localement en trois dimensions. Pour la démonstration, on a appliqué, dans le système vitreux Li₂O-Nb₂O₅-SiO₂ le mode opératoire décrit ci-dessous qui permet la formation de cristaux de LiNbO₃, hautement optiquement non linéaire. La procédure est la suivante : 1) ajustement de la composition chimique du verre pour obtenir un verre suffisamment sensible au laser fs ; 2) contrôle des paramètres du laser (durée d'impulsion, fréquence de répétition des impulsions, vitesse de balayage du faisceau, énergie d'impulsion…) pour obtenir des nanocristaux avec répartition spatiale et taille correcte. En outre, la taille de la zone affectée doit être limitée ; 3) contrôle de l'orientation des nanocristaux. On montre qu'il est possible de satisfaire à cette condition, en contrôlant l'orientation de la polarisation du laser. Ceci a été montré par la méthode de rétrodiffusion d'électrons de diffraction (EBSD). En d'autres termes, ce processus peut être contrôlé directement avec la lumière. En outre, la spectroscopie par rayons X à dispersion d'énergie couplée à la microscopie à transmission électronique à balayage (STEM /EDS) et la microscopie électronique à transmission a révélé une microstructure orientable similaire à celle appelée nanoréseaux formée dans silice. L'originalité est que les nanocristaux optiques non linéaires texturées noyées dans un réseau de "murs" vitreux, sont alignés perpendiculairement à la direction de polarisation du laser. Il en résulte que la biréfringence et la propriété optique non linéaire peuvent être maîtrisées ensemble. Ceci est une percée dans ce travail de thèse. Ces résultats mettent en évidence des modifications spectaculaires de verre par rayonnement laser fs. Avec de nouvelles améliorations dans les techniques de fabrication, l'application de ce travail est de parvenir à réaliser un guide d'ondes biréfringent doubleur ou changeur de fréquences
Due to random disorder, a glass exhibits inversion symmetry such that second harmonic generation (SHG) is forbidden. However, by irradiation with a tightly focused femtosecond (fs) laser, it is possible to induce nonlinear optical crystal precipitation, in order to break the inversion symmetry and thus to induce SHG. Moreover, this can be achieved locally in three dimensions. For demonstration, we applied the procedure described below in the glass system Li₂O-Nb₂O₅-SiO₂ that allows the formation of LiNbO₃ crystal, a highly non linear optical one. The procedure is thus the following: 1) adjustment of the glass chemical composition for obtaining a glass sensitive enough to fs laser. 2) control of the laser parameters (pulse duration, pulse repetition rate, speed of beam scanning, pulse energy…) for obtaining nanocrystals with correct space distribution and size. In addition, the size of the affected zone has to be limited. 3) control of the orientation of the nanocrystals. We show that it is possible to fulfill this condition by controlling the laser polarization orientation. This has been achieved by electron backscatter diffraction method (EBSD). In other words, this process can be controlled with light directly. In addition, energy dispersive X-ray spectroscopy coupled to scanning transmission electron microscopy (STEM/EDS) and transmission electron microscopy revealed an orientable microstructure similar to the one called nanogratings form in silica. The originality here is a textured nonlinear optical nanocrystals embedded in a network of “walls” made of vitreous phase, aligned perpendicular to the laser polarization direction. It results that birefringence and nonlinear optical property can be mastered in the same time. This is a highly valuable aspect of the work. These findings highlight spectacular modifications of glass by fs laser radiation. With further improvements in the fabrication techniques, the application of this work is to achieve SHG waveguide and birefringence-based devices
Styles APA, Harvard, Vancouver, ISO, etc.
3

FABIAN, FONZAR RICCARDO. « A study into mechanical, aesthetic and adhesive aspects of lithia silica-based glass ceramics ». Doctoral thesis, 2016. http://hdl.handle.net/2158/1029670.

Texte intégral
Résumé :
Lithia silica-based glass ceramics can be used in prosthetic dentistry to restore compromised or missing teeth. By modifying the chemical composition, silicates might vary in microstructure, formulations, processing methods, mechanical behaviour, and aesthetic appearance. Since the material selection might be also based on its mechanical properties, in the first investigation, the fracture resistance of CAD-CAM and heat-pressed lithium disilicate was evaluated and compared with regard to the translucency of the formulation and the processing method. By following a digital workflow, restorations are coarse in texture and opaque in aspect after milling. To make the surface compatible with the oral cavity, finishing procedures are necessary. In the second investigation, the efficacy of four finishing and polishing systems was tested on two lithia silica-based ceramics with standardized surfaces. After finishing, lithia silica-based restorations can be cemented with adhesive procedures. Micro-retentions and physico-chemical interactions are required to improve the adhesion between the resin cement and the intaglio surface. Since glass ceramics are hydrofluoric acid sensitive, in the third investigation, the effect of different etching protocols on the bond strength of two lithia silica-based ceramics with standardized surfaces was investigated.
Styles APA, Harvard, Vancouver, ISO, etc.
4

Traykova, Tania [Verfasser]. « Development and optimisation of calcium phosphate silica based ceramics for medical applications / von Tania Traykova ». 2003. http://d-nb.info/995665257/34.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
5

Lin, Wan-Yu, et 林宛諭. « Effect of Materials and Surface Roughness and Porosity on Silica-based Bio-ceramics for Osteoblasts Affinity ». Thesis, 2017. http://ndltd.ncl.edu.tw/handle/awkfdz.

Texte intégral
Résumé :
碩士
龍華科技大學
機械工程系碩士班
105
As the population ages, there is a tremendous clinical demand for artificial bone due to bone defects and decrease of bone regeneration rate. Therefore, in order to improve the efficiency of bone repair. A customized 3D bone scaffold was fabricated by a 3D printing process in this study, while discussing and focusing on three aspects: the materials, the surface roughness and the porosity. A screening platform was set up by changing the above-mentioned three factors to reduce the cell adhesion time, cell growth rate and allow the osteoblast to differentiate earlier, thus shortening the time to promote bone repair. In this experiment, a porous ceramic scaffold was made by using silica substrate and the influencing factors affecting bone regeneration were explored. Cells were cultured on the ceramic scaffold which fabricated by silica, calcium carbonate or zirconia and the growth rate of cells were tested. It was found that silicon dioxide had the best biocompatibility and biological properties to shorten cell adhesion and growth time. Different surface roughness can be changed by adjusting the different laser scanner pitches and by increasing the laser scanner pitch, the surface roughness will also increase. In vitro test, the results show that a laser scanning pitch of 0.1mm can generate a roughness height of 12.21μm, which is most effective in shortening the cell adhesion time. In porosity tests the solid porogen was added to the ceramic scaffold to increase their porosity. As the ratio of porogen increased in the ceramic scaffold, the more porous it becomes. In the cell adhesion test, the addition of 10% of graphite powder with particle size of 20 μm brought a porosity of 40% in ceramic scaffold, which could effectively shorten the cell adhesion time. Overall experiment results show that that ceramic scaffold fabricated by silica and silica sol with the ratio of 8:2 can increase the efficiency of cell adhesion, cell growth and differentiation rate. Therefore, these materials can be used to produce custom-made ceramic bone scaffold by 3D printing technology and then applied to the clinical in the future.
Styles APA, Harvard, Vancouver, ISO, etc.
6

Chen, Yu-Chia, et 陳育嘉. « The Effect of TiO2 and K2O on Optical Property and Laser-induced Crystallization in Cr-doped silica-based Glass and Glass-ceramics ». Thesis, 2012. http://ndltd.ncl.edu.tw/handle/19705584735850568867.

Texte intégral
Résumé :
碩士
國立中山大學
光電工程學系研究所
100
This thesis mainly studying the impact of TiO2 and K2O these two compounds in the Chromium-doped glasses and glass-ceramics. Due to the method of Modified Chemical Vapor Deposition (MCVD) of Chromium-doped fiber preform production process, the Ti and K elements have some difficulties; thus, we discuss the influences of these two elements. We hope to improve the composition after knowing these two elements, in order to make the Chromium-doped fiber preform well. We change the weight percent of TiO2 and K2O in the glass composition, in order to observe the influences. Then, we measure their optical and material properties. The results of experiments show that the well-known nucleation agent: TiO2, have no effect of the crystalline phase. However, its function is to help the formation of crystals. We can conclude by the results of X-ray Diffraction (XRD). K2O plays an important role of the Mg2SiO4 phase. To add K2O or not, is the most important reason to affect the Mg2SiO4 phase formation. We will discuss in detail in this thesis about the phase difference for the fluorescence characteristics of Chromium-doped glass and glass-ceramics. What’s more, we use the previously developed two times laser heat-treatment, hoping to successfully apply for Chromium-doped fiber drawing in the future. The laser heat-treatment of CO2-laser can induce the crystal in the glasses. However, this method only needs just a few seconds, which can reduce the cost of heat-treatment. In addition, we can reduce the crystalline size by using the method of two times laser heat-treatment, which can decrease the scattering loss. Also, we will discuss the impact of laser heat-treatment after changing the composition.
Styles APA, Harvard, Vancouver, ISO, etc.

Chapitres de livres sur le sujet "Lithia silica based ceramics"

1

Colilla, Montserrat. « Silica-based Ceramics : Mesoporous Silica ». Dans Bio-Ceramics with Clinical Applications, 109–51. Chichester, UK : John Wiley & Sons, Ltd, 2014. http://dx.doi.org/10.1002/9781118406748.ch5.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
2

Salinas, Antonio J. « Silica-based Ceramics : Glasses ». Dans Bio-Ceramics with Clinical Applications, 73–108. Chichester, UK : John Wiley & Sons, Ltd, 2014. http://dx.doi.org/10.1002/9781118406748.ch4.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
3

Rüssel, Christian. « Glass Ceramics : Silica- and Alumina-Based ». Dans Ceramics Science and Technology, 375–406. Weinheim, Germany : Wiley-VCH Verlag GmbH & Co. KGaA, 2011. http://dx.doi.org/10.1002/9783527631926.ch9.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
4

Rüssel, Christian. « Glass Ceramics : Silica- and Alumina-Based ». Dans Ceramics Science and Technology, 375–406. Weinheim, Germany : Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527631940.ch9.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
5

Weiss, Ester, et Raed Abu-Reziq. « Functional Particulated Ionic Liquid-Based Silica Microcapsules ». Dans Proceedings of the IV Advanced Ceramics and Applications Conference, 29–38. Paris : Atlantis Press, 2017. http://dx.doi.org/10.2991/978-94-6239-213-7_3.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
6

Li, Jie, Yuki Shirosaki, Satoshi Hayakawa et Akiyoshi Osaka. « Preparation and Protein Adsorption of Silica-Based Composite Particles for Blood Purification Therapy ». Dans Advances in Bioceramics and Porous Ceramics IV, 13–18. Hoboken, NJ, USA : John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118095263.ch2.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Gluth, G. J. G., P. Sturm, S. Greiser, C. Jäger et H. C. Kühne. « One-Part Geopolymers and Aluminosilicate Gel-Zeolite Composites Based On Silica : Factors Influencing Microstructure and Engineering Properties ». Dans Proceeding of the 42nd International Conference on Advanced Ceramics and Composites, 183–96. Hoboken, NJ, USA : John Wiley & Sons, Inc., 2019. http://dx.doi.org/10.1002/9781119543381.ch17.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
8

Rocha Pereira, Gabriel Kalil, Marília Pivetta Rippe et Luiz Felipe Valandro. « New Materials for CAD/CAM Systems : Resin-Based Composites, Polymer-Infiltrated Ceramic Network, Zirconia-Reinforced Lithium Silicate, and High Translucent Zirconia ». Dans Esthetic Oral Rehabilitation with Veneers, 211–33. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-41091-9_8.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
9

Ikram, Mujtaba, Sana Arbab, Bilal Tariq, Rayha Khan, Husnain Ahmad, Abdullah Khan Durran, Muhammad Ikram, Muhammad Aamir Iqbal et Asghari Maqsood. « Surface Science of Graphene-Based Monoliths and Their Electrical, Mechanical, and Energy Applications ». Dans 21st Century Surface Science - a Handbook. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.93318.

Texte intégral
Résumé :
Ceramic monoliths are applied in many insulating and high resistive engineering applications, but the energy application of ceramics monoliths is still vacant due to less conductivity of monolithic ceramics (for example, in silica- and alumina-based hybrids). This book chapter is a significant contribution in the graphene industry as it explains some novel and modified fabrication techniques for ceramics-graphene hybrids. The improved physical properties may be used to set ceramics-graphene hybrids as a standard for electrical, mechanical, thermal, and energy applications. Further, silica-rGO hybrids may be used as dielectric materials for high-temperature applications due to improved dielectric properties. The fabricated nano-assembly is important for a technological point of view, which may be further applied as electrolytes, catalysts, and conductive, electrochemically active, and dielectric materials for the high-temperature applications. In the end, this chapter discussed porous carbon as a massive source of electrochemical energy for supercapacitors and lithium-ion batteries. Carbon materials which are future of energy storage devices because of their ability to store energy in great capacity, so sustainability through smart materials got a huge potential, so hereby keeping in view all the technological aspects, this chapters sums up important contribution of graphene and porous carbon for applied applications.
Styles APA, Harvard, Vancouver, ISO, etc.
10

« Stimuli-Responsive Drug Delivery Systems Based on Mesoporous Silica ». Dans Biomedical Applications of Mesoporous Ceramics, 105–34. CRC Press, 2012. http://dx.doi.org/10.1201/b12959-4.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.

Actes de conférences sur le sujet "Lithia silica based ceramics"

1

Ueno, Shunkichi, Naoki Kondo, D. Doni Jayaseelan, Tatsuki Ohji et Shuzo Kanzaki. « High Temperature Hydro Corrosion Resistance of Silica Based Oxide Ceramics ». Dans ASME Turbo Expo 2003, collocated with the 2003 International Joint Power Generation Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/gt2003-38878.

Texte intégral
Résumé :
Water vapor corrosion behavior of Ln2Si2O7 (Ln = Nd, Er, Lu), mullite, CaYb4Si3O13 and Al2O3 were investigated at 1500°C. In Ln2Si2O7 phases, Ln = Nd and Er samples were completely dissolved in water vapor environment. CaYb4Si3O13 phase underwent decomposition during the corrosion test. Lu2Si2O7 and mullite showed excellent water vapor corrosion protection. In the case of mullite, Al2O3 rich phase was formed on the surface and the corrosion progression was successfully protected. In the case of Lu2Si2O7 phase, phase transition occurred and the grain boundaries of surface layer were slightly corroded by the corrosion test.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Suzuki, M., S. Sodeoka et T. Inoue. « Zircon-Based Ceramics Composite Coating for Environmental Barrier Coating ». Dans ITSC2007, sous la direction de B. R. Marple, M. M. Hyland, Y. C. Lau, C. J. Li, R. S. Lima et G. Montavon. ASM International, 2007. http://dx.doi.org/10.31399/asm.cp.itsc2007p0523.

Texte intégral
Résumé :
Abstract Studies on plasma spraying of zircon (ZrSiO4) have been carried out by the authors as one of the candidates for an environmental barrier coating (EBC) application, and had reported that substrate temperature is one of the most important factors to obtain crack-free and highly-adhesive coating. In this study, several amount of yttria were added to zircon powder, and the effect of the yttria addition on the structure and properties of the coatings were evaluated in order to improve the stability of the zircon coating structure at elevated temperature. The coatings obtained were composed of yttria stabilized zirconia (YSZ), glassy silica, while the one prepared from monolithic zircon powder composed of the metastable high temperature tetragonal phase of zirconia and glassy silica. After the heat treatment over 1473K, silica and zirconia formed zircon in all the coatings. However, the coatings with the higher amount of yttria had less amount of zircon formed. This resulted in the less open porosity of the coating at elevated temperature. These yttria added coatings also showed good adhesion even after the heat treatment, while monolithic zircon coating had pealed off.
Styles APA, Harvard, Vancouver, ISO, etc.
3

Bhatia, Tania, Venkat Vedula, Harry Eaton, Ellen Sun, John Holowczak et Gary Linsey. « Development and Evaluation of Environmental Barrier Coatings for Si-Based Ceramics ». Dans ASME Turbo Expo 2004 : Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-54092.

Texte intégral
Résumé :
Environmental barrier coatings (EBCs) are being developed for silicon carbide (SiC) based composites and monolithic silicon nitride (Si3N4) to protect against the accelerated oxidation and subsequent silica volatilization in high temperature, high-pressure steam environments encountered in gas turbine engines. While EBCs for silicon carbide (EBCSiC) have been demonstrated in combustor liner applications, efforts are ongoing in the development of EBC systems for silicon nitride (EBCSiN). The challenges of adapting EBCSiC to monolithic Si3N4 are discussed in this paper. Progress in the area of EBCSiN including development and performance during field tests and tests simulating engine conditions are reviewed.
Styles APA, Harvard, Vancouver, ISO, etc.
4

Tortorelli, Peter F., et Karren L. More. « Use of Very High Water-Vapor Pressures to Evaluate Candidate Compositions for Environmental Barrier Coatings ». Dans ASME Turbo Expo 2005 : Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-69064.

Texte intégral
Résumé :
Environmental barrier coatings (EBCs) are used to protect Si-based ceramics from accelerated oxidation and volatilization in the presence of elevated water-vapor pressures at high temperatures and high gas velocities. Previously, an analysis based on mass flux of volatilized species has shown that operating at very high H2O pressures can be used to compensate for the low gas velocities found in many laboratory exposure facilities so as to conduct first-stage screening of EBC compositions for volatility resistance. To test this prediction experimentally, a high-temperature furnace was modified to accommodate gas pressures of up to 20 atm and bulk specimens of barium-strontium aluminosilicate (BSAS), barium aluminosilicate (BAS), and strontium aluminosilicate (SAS), silica (SiO2), and silicon carbide (SiC) were exposed at 1250°C in 90% H2O-10% air. This set of materials provided an adequate spread in susceptibility to volatilization to evaluate the proposed approach because BSAS, BAS, and SAS are significantly more volatilization resistant in water-bearing environments than SiO2 and Si-bearing ceramics (such as SiC) that form silica under these conditions. The gravimetric results provided clear trends in volatilization resistance. The three aluminosilicates exhibited similar kinetic behavior and had significantly lower rates of mass losses than the SiO2 and SiC. These findings provided the experimental proof-of-principle for using high-pressure, low-gas-velocity exposures for qualitative differentiation of degrees of volatilization resistance among different candidate materials being developed for EBC applications.
Styles APA, Harvard, Vancouver, ISO, etc.
5

Zafred, Paolo R., Stephen W. Sofie et Paul S. Gentile. « Progress in Understanding Silica Transport Process and Effects in Solid Oxide Fuel Cell Performance ». Dans ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33297.

Texte intégral
Résumé :
One of the enabling technologies required for commercialization of high efficiency solid oxide fuel cell (SOFC) stacks is the development of low cost ceramic refractories capable of withstanding the harsh environment during start-up and steady state operation. Although low density, high purity fibrous alumina materials have been used for more than two decades in manufacturing of SOFC stack components, their low mechanical strength and high cost have precluded their use in the next generation pre-commercial generator modules. A current trend in SOFC stack design is to use high strength, low purity mullite bonded, cast ceramics which can be produced in large volume at a relatively low cost. Sufficient strength is required to provide structural support of the stack and its upper internals in addition to withstanding the severe thermal gradients in both steady state and transient conditions. To reduce costs while achieving suitable mechanical strength, thermal shock, and creep resistance, certain levels of silica and other impurities are present in the refractory ceramic. Silica, however, has been established to poison SOFC anodes thus degrading cell performance and stack life. Therefore, silica transport within the stack has become a dominant issue in SOFC generator design. As a result, an important design requirement for the stack ceramic materials is to develop a fundamental understanding of the silicon species transport process based on refractory composition and gas atmosphere in effort to minimize silicon species volatilization through the porous material. The vaporization behavior of the Al-Si-O system has been investigated in numerous studies and verified experimentally. It is well known that when aluminum silicate components are exposed to a reducing atmosphere, the partial pressure of oxygen is low, therefore this causes formation of volatile SiO(g). This SiO(g) gaseous phase is transported by the fuel stream to the anode/electrolyte interface and electrochemically oxidizes back into SiO2 over the triple phase boundaries (TPB) by the oxygen transported via the fuel cell. This re-deposition process of SiO2, known also as Si poisoning, blocks the reaction of fuel oxidation as it takes over the reactive sites, leading to noticeable degradation in cell performance. In this paper, the status of research on formation of volatile silicon species in aluminosilicate SOFC insulation materials is examined. The formation of volatile SiO(g), SiO(OH)(g), and SiO(OH)2(g) are indicated to facilitate silicon transport in anode fuel streams. Silica deposition is shown to degrade fuel cell anode performance utilizing a novel SOFC silicon poisoning test setup, and silica deposition is only observed on YSZ in the electrochemically active regions of the cell.
Styles APA, Harvard, Vancouver, ISO, etc.
6

Gates, Richard S., Z. Charles Ying et Stephen M. Hsu. « Tribochemical Reactions at the Water-Lubricated Silicon Nitride Interface : Gel Formation Mechanism ». Dans World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-64310.

Texte intégral
Résumé :
Silicon-based ceramics such as silicon nitride can be very effectively lubricated by water under certain conditions (1–3). After a wear-in period a condition of very low friction coefficient (<0.01) can be achieved for average contact pressures of 40 MPa and lower. Tomizawa & Fischer (1) proposed a chemomechanical polishing mechanism to reduce surface roughness enabling the onset of hydrodynamic lubrication by water. We suggest that there is an additional soft hydrated silica gel layer adhering to the rubbing surfaces that provides a deformable protective film to enable effective hydrodynamic lubrication of water and protect the surfaces from occasional asperity contacts. The existence of such films was indicated by the nanomechanical data performed on worn surfaces.
Styles APA, Harvard, Vancouver, ISO, etc.
7

Sun, Ellen Y., Harry E. Eaton, John E. Holowczak et Gary D. Linsey. « Development and Evaluation of Environmental Barrier Coatings for Silicon Nitride ». Dans ASME Turbo Expo 2002 : Power for Land, Sea, and Air. ASMEDC, 2002. http://dx.doi.org/10.1115/gt2002-30628.

Texte intégral
Résumé :
Environmental barrier coatings (EBCs) are required for applications of silicon nitride (Si3N4) and silicon carbide (SiC) based materials in gas turbine engines because of the accelerated oxidation of Si3N4 and SiC and subsequent volatilization of silica in the high temperature high-pressure steam environment. EBC systems for silicon carbide fiber reinforced silicon carbide ceramic matrix composites (SiC/SiC CMC’s) were first developed and have been demonstrated via long-term engine tests. Recently, studies have been carried out at United Technologies Research Center (UTRC) to understand the temperature capability of the current celsian-based EBC systems and its suitability for silicon nitride ceramics concerning thermal expansion mismatch between the EBC coating and silicon nitride substrates. This paper will present recent progress in improving the temperature capability of the celsian –based EBC systems and discuss their effectiveness for silicon nitride.
Styles APA, Harvard, Vancouver, ISO, etc.
8

Latzel, S., R. Vaßen et D. Stöver. « A New Environmental Barrier Coating System on Carbon-Fiber Reinforced Silicon Carbide Composites ». Dans ITSC2003, sous la direction de Basil R. Marple et Christian Moreau. ASM International, 2003. http://dx.doi.org/10.31399/asm.cp.itsc2003p1625.

Texte intégral
Résumé :
Abstract Carbon-fiber-reinforced silicon carbide composites (C/SiC) are promising materials for high temperature light weight structural components. However, a protective coating is necessary to prevent the oxidation of the carbon, especially at temperatures above 400 °C. Also the silica scale, which often forms on top of the C/SiC, must be protected from water vapor contact as the silica scale is not stable under these conditions. Hence, a protective coating, an Environmental Barrier Coating (EBC), is needed to shelter the material from the environmental influences of oxygen and water vapor. Current EBC systems employ multiple layers, each serving unique requirements. However, any mismatch in the coefficients of thermal expansion (CTE) leads to internal stress and results in crack formation. In this case, oxygen and water vapor penetrate through the EBC, reducing the lifetime of the component. Mullite (Al6Si2O13) is used in many known EBC systems on silicon-based ceramics either as an EBC itself or as a bondcoat. Due to its low CTE and its sufficient thermal cycling behaviour, mullite was chosen in this investigation as a first layer. As mullite suffers loss of SiO2 when exposed to water vapor at high temperatures, an additional protective top coat is needed to complete the EBC system. Different oxides were evaluated to serve as top coat, especially high temperature oxides with low coefficients of thermal expansion (LCTE). An Environmental Barrier Coating containing mullite as bondcoat and a LCTE oxide as a top coat is proposed. Both layers were applied via atmospheric plasma spraying. Results on the influence of processing conditions on the microstructure of single mullite and LCTE oxide layers and also mullite / LCTE oxide systems will be presented. Special emphasis was directed towards the crystallinity of the mullite layer, and in the top layer towards low porosity and reduced crack density.
Styles APA, Harvard, Vancouver, ISO, etc.

Rapports d'organisations sur le sujet "Lithia silica based ceramics"

1

Moddeman, W. E., R. E. Pence, R. T. Massey, R. T. Cassidy et D. P. Kramer. Sealing 304L to lithia-alumina-silica (LAS) glass-ceramics. Office of Scientific and Technical Information (OSTI), décembre 1989. http://dx.doi.org/10.2172/274153.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
Vous pouvez également être intéressé par les bibliographies sur le sujet « Lithia silica based ceramics » pour d’autres types de sources :
Articles de revues
Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!

Vers la bibliographie