Phase Evolutionary Process of CaO-Al2O3-SiO2 System Glass and Glass-Ceramic

2010 ◽  
Vol 168-170 ◽  
pp. 1947-1952
Author(s):  
Feng He ◽  
Cai Ming Ping ◽  
Jin Shu Cheng
Keyword(s):  
Heat Treatment ◽  
Glass Ceramic ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Evolutionary Process ◽  
Treatment Schedule ◽  
Nucleation Agent ◽  
Transmission Electron ◽  
New Type ◽  
Heat Treatment Schedule

Sintering glass-ceramics, a new type material for architectural decoration, belong to CaO-Al2O3-SiO2system (CAS) without nucleation agent. Combined by Differential thermal analysis (DTA), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Transmission electron microscope (TEM), phase evolutionary process of CaO-Al2O3-SiO2system glass and glass-ceramic was investigated. According the relation between heat treatment schedule and microstructure, the glass system has a very wide temperature range of crystallization. The crystalline phase is β-CaSiO3(β-wollastonite) and there is no other crystalline phases precipitated in these glass-ceramics. The influences of various heat treatment systems on the structure and properties of the glass-ceramics were investigated simultaneously. The optimal heat treatment schedule, microstructure and bending strength of the CAS glass ceramic were gained.

Nucleation and Crystallization of Glass-Ceramics from Coal Fly Ash

2007 ◽  
Vol 280-283 ◽  
pp. 1651-1654 ◽  
Author(s):  
Fei Peng ◽  
Kai Ming Liang ◽  
Hua Shao ◽  
An Min Hu ◽  
Feng Zhou
Keyword(s):  
Activation Energy ◽  
Fly Ash ◽  
Coal Fly Ash ◽  
Glass Ceramics ◽  
Treatment Schedule ◽  
Nucleation Agent ◽  
Optimum Heat ◽  
Heat Treatment Schedule ◽  
Kinetics Of ◽  
Optimum Heat Treatment

The nucleation and crystallization kinetics of glass obtained by melting coal fly ash with additives at 1550°C have been investigated. The optimum heat treatment schedule for the glass was nucleation at 825°C for 60min before crystallization at 962°C for 4h. The activation energy for crystallization of the glass-ceramics, obtained by the DDTA result, was 280.03 kJ/mol, lower than that of glass-ceramics obtained from pure reagents. The low activation energy is caused by impurities in fly ash, serving as nucleation agent. The results of XRD and SEM show that glass-ceramics developed nano-sized spherical wollastonite.

Formation and Passive Q-Switch Performance of Glass-Ceramics Containing Co2+-Doped Spinel Nanocrystals

2008 ◽  
Vol 39-40 ◽  
pp. 219-224 ◽  
Author(s):  
Olga Dymshits ◽  
Alexander Shashkin ◽  
Alexander A. Zhilin ◽  
Yury Volk ◽  
Alexander Malyarevich ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cross Sections ◽  
Near Infrared ◽  
Glass Ceramics ◽  
Excited State Absorption ◽  
Output Pulse ◽  
Treatment Schedule ◽  
Transparent Glass ◽  
Treatment Conditions ◽  
Heat Treatment Schedule

Compositions and heat treatment conditions were determined at which absorption and luminescence properties of aluminosilicate transparent glass-ceramics are defined mainly by tetrahedrally coordinated Co2+ ions located in spinel nanocrystals. Optical properties of cobaltdoped aluminosilicate transparent glass-ceramics have been studied in visible – near infrared (IR) spectral range. It was demonstrated that the concentration of tetrahedrally coordinated Co2+ ions in the spinel nanocrystals is determined by the CoO content in the initial glass and is independent of the heat-treatment schedule. Absorption saturation and bleaching relaxation under excitation of the 4A2→4T1(4F) transition of tetrahedrally coordinated Co2+ ions were studied. The value of groundstate and excited state absorption cross-sections of tetrahedrally coordinated Co2+ ions was estimated. Comparative study of output pulse parameters of Q-switched Er:glass laser using cobaltdoped glass-ceramics and Co2+:MgAl2O4 single crystal is presented.

scholarly journals Study of PbTiO3-Based Glass Ceramics Containing SiO2

ISRN Ceramics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
V. K. Deshpande ◽  
V. U. Rahangdale
Keyword(s):  
Dielectric Constant ◽  
Glass Ceramic ◽  
Lead Titanate ◽  
Glass Ceramics ◽  
Treatment Schedule ◽  
Glass Ceramic Sample ◽  
Practical Applications ◽  
Ceramic Samples ◽  
Heat Treatment Schedule ◽  
Stage Heat Treatment

Glass samples with composition 50PbO : 25TiO2 : (25-X) B2O3 : XSiO2 (with X = 0, 1.5, 2.5, 3.5, and 5 mol%) were prepared by conventional quenching technique. These glass samples were converted to glass ceramics by the two-stage heat treatment schedule. Formation of ferroelectric lead titanate phase in the glass ceramics was confirmed from the XRD. The density, CTE, and dielectric constant of the glass and glass-ceramic samples were measured. The glass-ceramic sample containing 2.5 mol% SiO2 exhibited the highest dielectric constant. The SEMs of glass-ceramic samples were studied. The P-E hysteresis loop studies also revealed the highest remnant polarization for this sample, which has a potential for being developed for practical applications.

Effect of Cerium Oxide on Sinterability, Microstructure and Properties of Anorthite-Based Glass/Ceramic Composites

2013 ◽  
Vol 544 ◽  
pp. 52-55 ◽  
Author(s):  
Wei Xia Dong ◽  
Qi Fu Bao ◽  
Xing Yong Gu ◽  
Yan Chun Huang
Keyword(s):  
Thermal Expansion ◽  
Glass Ceramic ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Ceramic Composites ◽  
Scanning Transmission Electron Microscope ◽  
Sintering Behavior ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Doped Glass

The properties of anorthite-based glass/ceramic with different amounts of CeO2 addition had been investigated in this paper. The glass/ceramics with small amounts of CeO2 addition could be well sintered at 850~900°C. The water absorption was examined to evaluate the sintering behavior of the samples. The crystalline phase,microstructure, dielectric properties, thermal expansion and bending strength were characterized by X-Ray diffraction (XRD), scanning transmission electron microscope (SEM), impedance materials analyzer, thermal expansion analyzer and flexural strength analyzer. The results showed the 1wt % CeO2-doped glass/ceramics sintered at 900 °C have optimum properties of ε = 6.282, tanθ = 2.18×10-3 at 1 MHz and a thermal expansion coefficient of 3.32×10-6 °C-1 (25~500 oC) matched with silicon chip (3.4×10-6 °C -1). Obviously, CeO2 could be used as a suitable sintering aid that improves densification of the glass/ceramic composites.

An MgB2 Superconducting Joint with its Own Heat-Treatment Schedule

2021 ◽  
pp. 1-1
Author(s):  
Hiromi Tanaka ◽  
Yi Li ◽  
Yoonhyuck Choi ◽  
Dongkeun Park ◽  
Wooseung Lee ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Treatment Schedule ◽  
Heat Treatment Schedule

scholarly journals Bone bonding ability of some borate bio-glasses and their corresponding glass-ceramic derivatives

2012 ◽  
Vol 6 (4) ◽  
pp. 183-192 ◽  
Author(s):  
Fatma Margha ◽  
Amr Abdelghany
Keyword(s):  
Heat Treatment ◽  
Fourier Transform ◽  
Glass Ceramic ◽  
Glass Composition ◽  
Glass Ceramics ◽  
Soda Lime ◽  
Phosphate Solution ◽  
Borate Glasses ◽  
X Ray Diffraction ◽  
X Ray

Ternary borate glasses from the system Na2O?CaO?B2O3 together with soda-lime-borate samples containing 5 wt.% of MgO, Al2O3, SiO2 or P2O5 were prepared. The obtained glasses were converted to their glass-ceramic derivatives by controlled heat treatment. X-ray diffraction was employed to investigate the separated crys?talline phases in glass-ceramics after heat treatment of the glassy samples. The glasses and corresponding glass-ceramics after immersion in water or diluted phosphate solution for extended times were characterized by the grain method (adopted by several authors and recommended by ASTM) and Fourier-transform infrared spectra to justify the formation of hydroxyapatite as an indication of the bone bonding ability. The influence of glass composition on bioactivity potential was discussed too.

Structure Characterization of Sintered CaO-Al2O3-SiO2 Glass-Ceramic Reinforced with Spodumene

2013 ◽  
Vol 834-836 ◽  
pp. 309-314
Author(s):  
Zi Fan Xiao ◽  
Jin Shu Cheng ◽  
Jun Xie
Keyword(s):  
Glass Ceramic ◽  
Energy Dispersive Spectrometry ◽  
Crystal Size ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray

A glass-ceramic belonging to the CaO-Al2O3-SiO2(CAS) system with different composition of spodumene and doping the Li2O with amount between 0~2.5 % (mass fraction) were prepared by onestage heat treatment, under sintering and crystallization temperature at 1120 °C for two hours. In this paper, differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and bending strength test were employed to investigate the microstructure and properties of all samples. β-wollastonite crystals were identified as the major crystalline phases, and increasing Li2O was found to be benefit for the crystallization and tiny crystalline phases remelting, resulting in the content of major crystalline phases increased first and then decreased with increasing the expense of spodumene. Meanwhile, the crystal size can be positively related with the content of Li2O. The preferable admixed dosage of spodumene can be obtained, besides the strength of glass-ceramics can be more than 90 MPa.

Sign in / Sign up

Export Citation Format

Share Document