Insight into the roles of the glassy phase in glass-ceramics during the cascade collisions

2021 ◽  
Vol 199 ◽  
pp. 110706
Author(s):  
Shuohua Zhang ◽  
Xiaoguang Guo ◽  
Song Yuan ◽  
Ming Li ◽  
Zhuji Jin ◽  
...  
Keyword(s):  
Glassy Phase ◽  
Glass Ceramics ◽  
Insight Into

scholarly journals Preparation of basalt-based glass ceramics

2003 ◽  
Vol 68 (6) ◽  
pp. 505-510 ◽  
Author(s):  
Branko Matovic ◽  
Snezana Boskovic ◽  
Mihovil Logar
Keyword(s):  
Optical Microscopy ◽  
Phase Analysis ◽  
Glass Ceramic ◽  
Glassy Phase ◽  
Raw Materials ◽  
Glass Ceramics ◽  
High Strength ◽  
Ceramic Materials ◽  
X Ray ◽  
Glass Ceramic Materials

Local and conventional raw materials?massive basalt from the Vrelo locality on Kopaonik mountain?have been used as starting materials to test their suitability for the production of glass-ceramics. Crystallization phenomena of glasses of the fused basalt rocks were studied by X-ray phase analysis optical microscopy and other techniques. Various heat treatments were used and their influences, on controlling the microstructures and properties of the products were studied with the aim of developing high strength glass-ceramic materials. Diopside CaMg(SiO3)2 and hypersthene ((Mg,Fe)SiO3) were identifies as the crystalline phases. The final products contained considerable amounts of a glassy phase. The crystalline size was in range of 8?480 ?m with plate or needle shape. Microhardness, crashing strength and wears resistence of the glass-ceramics ranged from 6.5?7.5, from 2000?6300 kg/cm2 and from 0.1?0.2 g/cm, respectively.

Atomistic insight into the structure and diffusion properties of pollucite glass-ceramics

2022 ◽  
Author(s):  
Hualong Yang ◽  
Siqi Ma ◽  
Wenjiu Duan ◽  
Shengjian Zhao ◽  
Qikun Wang ◽  
...  
Keyword(s):  
Glass Ceramics ◽  
And Diffusion ◽  
Insight Into ◽  
Diffusion Properties

Near-Net-Shape Forming of Celsian Ceramics from Ion-Exchanged Zeolite Precursors

1994 ◽  
Vol 346 ◽  
Author(s):  
Bahar Hoghooghi ◽  
Joanna Mckittrick ◽  
Chad Butler ◽  
Eugene Helsel ◽  
Olivia Lopez
Keyword(s):  
Heat Treatment ◽  
Ion Exchange ◽  
Glassy Phase ◽  
Glass Ceramics ◽  
Ceramic Phase ◽  
Seed Particles ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Precursor Powders ◽  
Zeolite Precursors

ABSTRACTA technique has been developed for the synthesis and near-net-shape forming of celsian glass-ceramics. This technique involves ion exchange of zeolite precursor powders, heat treatment of the powders to temperatures between 800–90°C to form a glassy phase during which the samples are formed under low stresses (<20 MPa). Upon further heat treatment to about 1000°C, crystallization occurs and the amorphous formed body is transformed to the celsian ceramic phase. Using this technique, and through the addition of monoclinic seed particles as well as a mineralizer, monoclinic celsian was produced at temperatures as low as 1000°C at heat treatment times of less than one hour. This forming technique also resulted in a significant reduction in the porosity of the ceramic bodies compared to free-sintered samples.

scholarly journals High Electronically Conductive Tungsten Phosphate Glass-Ceramics

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2515
Author(s):  
Sanja Renka ◽  
Teodoro Klaser ◽  
Sanja Burazer ◽  
Petr Mošner ◽  
Petr Kalenda ◽  
...  
Keyword(s):  
Solid State ◽  
Phosphate Glass ◽  
Electronic Transport ◽  
Anode Materials ◽  
Glass Ceramics ◽  
Solid State Batteries ◽  
Controlled Crystallization ◽  
Wo3 Phases ◽  
Average Size ◽  
Insight Into

High electronically conductive tungsten phosphate glass-ceramics have been prepared by the controlled crystallization of binary 60WO3–40P2O5 glass in the temperature range from 700 to 935 °C and for 1 to 24 h. The substantial increase in the conductivity for four orders of magnitude is a result of the formation of electronically conductive W2O3(PO4)2 and WO3 phases. At low crystallization temperature the dominant W2O3(PO4)2 phase is created, whereas at 935 °C for 24 h the formation of semiconducting WO3 crystallites of an average size of 80 nm enhances the conductivity to the highest value of 1.64 × 10−4 (Ω cm)–1 at 30 °C. The course of the crystallization and its impact on this exceptionally high electronic transport of binary tungsten phosphate glass-ceramics has been discussed in detail. Since such highly electronically conductive WO3-based glass-ceramics have a great potential as cathode/anode materials in solid state batteries and as electrocatalysts in fuel cells, it is of interest to provide a novel insight into the improvement of their electrical properties.

scholarly journals Physico-chemical properties and structural transformations in the synthesis of boroalumosilicate glass-crystal materials

2021 ◽  
pp. 3-8
Keyword(s):  
Crystallization Process ◽  
Glassy Phase ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
Glass Crystallization ◽  
Crystalline Materials ◽  
Thermophysical Parameters ◽  
Physico Chemical ◽  
Glass Crystal ◽  
Stage Heat Treatment

The aim of this work is to study the areas of glass formation and metastable liquation of the pseudo-ternary system (MgO·Al2O3)-B2O3-SiO2, and study of the crystallization process of glasses of cordierite composition. The crystallization process of glasses of cordierite composition containing B2O3 by a single-stage heat treatment at 1000 oC and 1200 oC, the nature of crystallization, the thermal properties of glasses and glass crystalline materials of the system (MgO·Al2O3)-B2O3-SiO2 were studied. It revealed that during the isolation of a boron-containing solid solution, the residual glassy phase enriched with oxides of MgO and Al2O3, which lead to an increase in the thermal expansion coefficient of the glass phase. The research results provide possibility to synthesize glass-ceramics with certain thermophysical parameters by stopping further glass crystallization at the stage of formation of a certain amount and ratio of the required crystalline and glassy phases.

Magnetic and Electric Properties of Phase Separated Glass Ceramics in CoO–TiO2–SiO2 System Prepared by Melt Quenching Process

2008 ◽  
Vol 1118 ◽  
Author(s):  
Hiroki Nakamura ◽  
Tetsuo Kishi ◽  
Yuji Muro ◽  
Ryuji Tamura ◽  
Kazuyasu Tokiwa ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Glassy Phase ◽  
Glass Ceramics ◽  
The Other ◽  
Melt Quenching ◽  
Nano Structure ◽  
Quenching Process ◽  
Magnetic And Electric Properties ◽  
Co Doped

ABSTRACTThe developments of high performance magnetic materials are required in various applications such as high sensitive magnetic sensing and hyperthermia in cancer treatment. Recently, Co-doped TiO2 has been received considerable attention as a candidate for such materials because of their ferromagnetic properties at room temperature. On the other hand, the phase-separated glasses and the derived glass-ceramics having unique micro-nano structure are utilized for various applications. In this study, the phase separated glass-ceramics in CoO-TiO2-SiO2 system with Al2O3 addition were prepared by melt-quenching process. The as-quenched samples consisted of the TiO2-rich phase and the SiO2-rich one which were formed by a nucleation-growth mechanism of phase separation. From the results of XRD measurements, the samples were found to have a TiO2 crystalline phase and a SiO2-rich glassy phase. The samples showed the magnetic property, which were regarded as a mixture of ferromagnetic and paramagnetic phases. The samples also showed the electric conductivity at room temperature. However, the conductivity of the sample decreased with increase of the Co content, and the temperature dependence of the conductivity of the ferromagnetic samples was different from the other ones. As a result, the Co ions in the phase-separated glass-ceramics in TiO2-SiO2 system were found to affect on both the magnetic and the electric conductive characteristics.

Preparation of Apatite-Containing Calcium Phosphate Glass-Ceramics

2007 ◽  
Vol 330-332 ◽  
pp. 157-160 ◽  
Author(s):  
Toshihiro Kasuga ◽  
Emiko Ueno ◽  
Akiko Obata
Keyword(s):  
Glass Ceramic ◽  
Glassy Phase ◽  
Glass Ceramics ◽  
Chemical Durability ◽  
Apatite Crystal ◽  
Tio2 Anatase ◽  
Step Heating ◽  
New Type ◽  
Titanium Phosphates ◽  
Excellent Chemical

A new type of glass-ceramic for novel dental fillers, which require excellent chemical durability, was investigated. A 40CaO-5CaF2-25TiO2-30P2O5 (in mol%) glass-ceramic was newly suggested. The glass-ceramic was prepared by a conventional two-step heating method. The resulting glass-ceramic included Nasicontype-CaTi4(PO4)6, titanium phosphates, such as (TiO)2P2O7 and Ti(PO3)3, and TiO2 (anatase) with apatite crystal, which was induced by incorporation of fluorine. In the glass-ceramic, dissolution by acid-treatment was strictly controlled. The excellent chemical durability of the glass-ceramic was suggested to originate from increase in the amount of the crystalline phases and a high content of titanium constituent in the residual glassy phase.

scholarly journals New insight into two-step near-infrared quantum cutting in Pr^3+ singly doped oxyfluoride glass-ceramics

2015 ◽  
Vol 6 (1) ◽  
pp. 197 ◽  
Author(s):  
D. C. Yu ◽  
Q. J. Chen ◽  
H. H. Lin ◽  
Y. Z. Wang ◽  
Q. Y. Zhang
Keyword(s):  
Near Infrared ◽  
Glass Ceramics ◽  
Oxyfluoride Glass ◽  
Quantum Cutting ◽  
Insight Into

Calibration problems in hydrogen luminosities

1966 ◽  
Vol 24 ◽  
pp. 322-330
Author(s):  
A. Beer
Keyword(s):  
Galactic Structure ◽  
B Stars ◽  
Insight Into

The investigations which I should like to summarize in this paper concern recent photo-electric luminosity determinations of O and B stars. Their final aim has been the derivation of new stellar distances, and some insight into certain patterns of galactic structure.

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