Catalyzed controlled crystallization of glasses in the lithium aluminosilicate system.

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Consultants Bureau , New York
Glass-ceramics., Titanium di
StatementEdited by V.V. Vargin. Authorized translation from the Russian by E. B. Uvarov.
ContributionsVargin, V. V., ed.
Classifications
LC ClassificationsTP862 .K313
The Physical Object
Pagination v.
ID Numbers
Open LibraryOL5952150M
LC Control Number65025265
OCLC/WorldCa2132898

Abstract. In accordance with the concepts put forward by Petrovskii and Nemilov [1], the determining process in the formation of glassceramics in the lithium aluminosilicate system is switching of covalent bonds and change of the coordination of titanium and aluminum with respect to : G.

Petrovskii, E. Krestnikova, N. Grebenshchikova. Additional Physical Format: Online version: Catalyzed controlled crystallization of glasses in the lithium aluminosilicate system. New York, Consultants Bureau, The Lithium Aluminosilicate System. Front Matter. Pages PDF. Mechanism of the Catalyzed Crystallization of Glasses in the Li 2 O-Al 2 O 3-SiO 2 System with Titanium Dioxide.

Podushko, A.

Description Catalyzed controlled crystallization of glasses in the lithium aluminosilicate system. PDF

Kozlova. About this book. Keywords. crystal crystallization. Bibliographic information. The spontaneous and catalyzed nucleation of crystals in the glasses of Li2O – SiO2 system caused by the addition of photosensitive impurities and X-ray irradiation was analyzed in glasses with a.

Abstract. We investigated crystal formation in lithium glasses starting from the binary system Li 2 OSiO 2, with gradual complication of the composition by introduction of photosensitive additives: (Ag + CeO 2), K 2 O, and A1 2 O glasses were crystallized in thin layers.

The glass was powdered down to grains – mm in size and crystallized in 5-cm 3 porcelain crucibles for 5 min at Author: N. Shmeleva, N. Ivanova. Structural transformations have been studied in glasses related in composition to the binary eutectic between lithium metasilicate and β-spodumene.

Crystallisation processes and changes in microstructure during the controlled heating of the glasses have been followed using X-ray diffraction, electron microscopy, high temperature microscopy, thermal analysis and electron spin resonance. Near-zero thermal expansion transparent lithium aluminosilicate glass-ceramic by microwave hybrid heat treatment.

Crystal Growth and Nucleation in Glasses in the Lithium Silicate System. Journal of Crystallization Process and Technology Design and control of crystallization in oxide glasses. Journal of Non-Crystalline Solids The structure and properties of lithium aluminosilicate glasses containing Y2O3 were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis (DTA) and Raman spectroscopy.

Effects of yttria on the viscosity of LAS glasses were investigated, and found that the introduction of yttria effectively decreased the viscosity of LAS glasses. Rates of crystallization of Li 2 O 2SiO 2, from an Li 2 O 4SiO 2 glass as a function of platinum concentration at ° and ° C were determined.

At both temperatures a maximum rate was obtained in the region of % Pt. Calculations of the activation energies for the crystallization process showed that %, Pt lowered it to less than half its original value of kcal per mole.

Kalinina, V. Filipovich, Study of the sequence of crystallization in the heating of lithium aluminosilicate glasses, Bulletin of the Academy of Sciences, USSR Division of Chemical Science, /BF, 14, 2, (), (). Catalyzed Controlled Crystallization of Glasses in the Lithium Aluminosilicate System.

Consultants Bureau, New York.

Details Catalyzed controlled crystallization of glasses in the lithium aluminosilicate system. EPUB

us of rupture values for the composite materials is much more difficult because the majority of research involving LAS/SiC reinforced composites utilizes continuous Nicalon SiC fiber to produce unidirectionally reinforced or.

The effect of ZrO2 on the nucleation of lithium metasilicate crystals in lithium disilicate-based multicomponent glasses of composition in wt% x ZrO2 + (1 - (x/)) ( SiO2 + K2O + Olga García‐Moreno, Waltraud M.

Kriven, José Serafín Moya, Ramón Torrecillas, Alumina Region of the Lithium Aluminosilicate System: A New Catalyzed Controlled Crystallization of Glasses in the Lithium Aluminosilicate System S.N.

Salama, Thermal expansion data of some alkali aluminosilicate glasses and their. The melting and crystallization behaviors of lithium aluminosilicate (LAS) glasses containing Y2O3 were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential.

The glass composition is close to the B-spodumene ternary compound in the lithium aluminosilicate system and includes ZrO2 and TiO2 as nucleating agents (Table 1).

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For the crystallization study, the as-received gel powder was calcined in flowing air at per minute to and held for 6 h, the lowest temperature-time condition to obtain.

Crystallization of TiO 2-free glasses was relatively dependent on the nominal ratio and the heat treatments as well, however, the lithium aluminosilicate phases were usually dominant. Catalyzed Crystallization of Glass / Katalizirovannaya Kristallizatsiya Stekla / Катализированная Кристаллизация Стекла.

Abstract An attempt is made to apply the ideas of crystal chemistry to the problem of immiscibility in glass systems. Survey of the Literature on Crystallization Processes in Glasses, Catalyzed Controlled Crystallization of Glasses in the Lithium Aluminosilicate System / Katalizirovannaya Reguliruemaya Kristallizatsiya Stekol.

--Lithium Glasses and Some of Their Crystallization Characteristics --The Lithium Aluminosilicate System --Mechanism of the Catalyzed Crystallization of Glasses in the Li2O-Al2O3-SiO2 System with Titanium Dioxide --Use of the #x00C9;M-7 Electron Microscope for Investigation of Crystal Lattices and Observation of Dislocations in Them --Electron.

In lithium aluminosilicate gels, the crystalline phases and the temperatures at which they appear depend on the preparation method used. Samples were prepared by adding anhydrous tetraethyl orthosilicate (TEOS) to a solution of methanol, water and the nitrates of lithium and aluminium.

The amount of methanol in the solution was varied to create miscible and immiscible compositions. This research managed to prepare LAS glasses doped with Nd 3+ ions by the conventional melting and quenching technique, at a relatively low melting temperature and by the use of some additives.

Lithium aluminosilicate glasses were transformed to glass-ceramics by controlled nucleation and the crystallization process. The crystallization of glasses richer in Al2O3 and K2O was dominated by surface nucleation leading to crystallization of lithium metasilicate (Li2SiO3) within the temperature range of – °C.

Host glasses are aluminosilicate glasses containing PbF 2 and their nominal compositions are in Table Rare earths were additionally doped up to 1 mol% of host glass composition. Chemical powders with purities of >% were weighed and mixed thoroughly for the melting in alumina crucibles at °C for 30 min under ambient atmosphere.

This note is part of a paper entitled “Subsolidus Nucleation in the System Li 2 O‐Al 2 O 3 ‐SiO 2 ” that was presented by Rustum Roy and C. Ruiz‐Menacho a t the Sixty‐First Annual Meeting The American Ceramic Society, Chicago, Ill., (White Wares Division, No. 4‐W‐59); see Am. Ceram. Soc.

Bull., 38 [4] () for an abstract of this paper. The Li2OSiO2 related glass systems have attracted extensive theoretical and experimental investigations for several decades. There are three different crystallization sequences commonly reported in lithium disilicate glasses although their contributing factors are unclear.

Moreover, the effect of concurrent precipitation of crystalline phases during glass crystallization is rarely reported.

Most probably the beta-quartz solid solution (SS) nanocrystal generation in lithium aluminosilicate (Li 2 O Al 2 O 3 SiO 2, LAS) glass system using suitable nucleating agent (e.g., TiO 2, ZrO 2, or TiO 2 ZrO 2) and heat-treatment schedule is the first example of the GCNCs.

In fact, this invention is the landmark discovery in the history of GCNCs. uniform bulk crystallization with fine-grained microstructure was achieved by an addition of TiO2 or CaF2 rather than LiF. The role of the nucleating agents during the formation of the crystal phases and the microstructure of the resultant glass--ceramics are discussed.

Keywords: Crystallization, Aluminosilicate glasses. The crystal growth and nucleation in glasses in the lithium silicate syshave betem en investigated. Phase separation in ultimately homogenized glasses of the lithium sili-cate system xLi 2O⋅( − x)SiO 2 (where x =,and mol% Li 2O) has been studied.

The glasses of these compositions have been homogenized using the. regarding the control crystallization in glass ceramic synthesis. In fact, the first prepared glass ceramics were developed by Stookey [1] by heat treatment of glass from this system.

The research on lithium disilicate glass ceramics can by classified into two categories in general. The first one deals with the study of binary sys-tem. Structure and Crystallization of Glasses details glass structural analysis from an experimental perspective. The book is comprised of eight chapters that cover various structural concepts.

The text first introduces the basic elements of glass structures, and then proceeds to discussing the development of classical structure theories. From glasses with the composition SiO2 MgO Al2O3 ZrO2 (in mol %), high and low-quartz solid solution glass ceramics were formed upon heat treatment at °C for different dwell times.

A combination of X-ray diffractometry, transmission electron microscopy, and scanning transmission electron microscopy with annular dark field imaging and energy-dispersive X-ray analysis.ENGLISH DESCRIPTION Book Condition: Used, Very good.

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