Nucleation, Crystallization and Characterization of Mica-Based Glass-Ceramics with Fluorapatite

2014 ◽  
Vol 936 ◽  
pp. 164-169 ◽  
Author(s):  
Jia Bai ◽  
Duangrudee Chaysuwan
Keyword(s):  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Soaking Time ◽  
X Ray ◽  
Optimal Heat Treatment ◽  
Treatment Conditions ◽  
Quenched Glass ◽  
Dental Applications ◽  
Soaking Temperature

The glass system of SiO2-Al2O3-MgO-MgF2-SrCO3-CaCO3-CaF2-P2O5 was used to prepare machinable glass-ceramics for restorative dental applications. The aim of this study was to apply various heat treatments to produce mica-based glass-ceramics. Differential Thermal Analysis (DTA) was used to determine the optimal heat treatment conditions for nucleation and growth of the crystalline phases in the quenched glass. It was found that the optimum nucleation temperatures for the first and the second crystallization temperatures (Tp1 and Tp2) were 642°C and 635°C, respectively, and the optimum nucleation times were between 2 and 4 hours. X-Ray Diffraction (XRD) showed the phases developed were anorthite, calcium-mica, fluorapatite, strontium apatite, forsterite, fluorite and stishovite phases. The microstructures of glass-ceramics were observed by Scanning electron microscope (SEM), found to exhibit plate-like mica crystals with high interlocking and randomly oriented with a higher soaking temperature and prolongation of the soaking time for crystallization.

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.

The Effects of Preparation Conditions And Chemical Composition On CMAS Glass Ceramics With One Step Process

2021 ◽  
Author(s):  
Yuliang Guo ◽  
Huixin Jin ◽  
Yuandan Xiao ◽  
Huahao Song ◽  
Shangjiefu Wang
Keyword(s):  
Solid Waste ◽  
Theoretical Basis ◽  
Chromium Content ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Crystallization Activation Energy ◽  
X Ray ◽  
Preparation Conditions ◽  
Treatment Conditions ◽  
One Step

Abstract Based on the composition of Cr-doped solid waste, other oxides were added to adjust the composition to prepare glass-ceramics with on step composition, and the effect of heat treatment system (including temperature and holding time), chromium content, MnO and Fe2O3 doped on the crystallization and physical properties of glass-ceramics was studied. The samples were characterized by X-ray diffraction, differential thermal analysis and scanning electron microscopy. The results show that the best treatment conditions are 1090 ℃ for 4h, and the amount of dissolved chromium reaches 5%. The main crystallization phase is diopside and anorthite. The hardness and chemical stability of the material were measured. The doping of MnO and Fe2O3 increases the crystallization activation energy of glass ceramics, and makes the crystal phase more uniform as the SEM results. This experiment provides a theoretical basis for the preparation of CMAS glass ceramics from chromium containing solid waste.

Neodymium Incorporation in Zirconolite-Based Glass-Ceramics

2000 ◽  
Vol 663 ◽  
Author(s):  
P. Loiseau ◽  
D. Caurant ◽  
N. Baffier ◽  
C. Fillet
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Fission Products ◽  
Treatment Temperature ◽  
Spent Fuel ◽  
X Ray Diffraction ◽  
Parent Glass ◽  
X Ray ◽  
Spin Resonance

ABSTRACTThe investigations on enhanced reprocessing of nuclear spent fuel, and notably on separating the long-lived minor actinides, such as Am and Cm, from the other fission products have led to the development of highly durable specific matrices such as glass-ceramics for their immobilization. This study deals with the characterization of zirconolite (CaZrTi2O7) based glass-ceramics synthesized by devitrification of an aluminosilicate parent glass. Trivalent actinide ions were simulated by neodymium, which is a paramagnetic local probe. Glass-ceramics with Nd2O3 contents ranging from 0 to 10 weight % were prepared by heat treatment of a parent glass at two different growth temperatures: 1050° and 1200°C. X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and electron spin resonance (ESR) measurements clearly indicate that Nd3+ ions are partly incorporated in zirconolite crystals formed in the bulk of the glass-ceramic samples. The amount of neodymium in the crystalline phase was estimated using ESR results and was found to decrease with increasing either heat treatment temperature or total Nd2O3 content.

Microstructure and Growth Mechanism of Glucose-Carburized Nickel Substrates

2013 ◽  
Vol 716 ◽  
pp. 153-158
Author(s):  
E.M. Pechlivani ◽  
G. Stergioudis ◽  
E. Pavlidou ◽  
S. Skolianos ◽  
D. Tsipas
Keyword(s):  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Temperature Treatment ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treatment Conditions ◽  
Nickel Substrates ◽  
Current Densities

In this research, efforts were made to study the modification of microstructure of pure Ni matrices. Modification was attempted using glucose as carburizing medium under a control of heat treatment conditions. Nickel plates were carburized under vacuum conditions at 380°C and 650°C for 3 hours. In order to determine the parameters of the carburizing, thermal properties of glucose along with the thermochemical behavior were examined by Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA). The characterization of the microstructure of the carburized specimens was investigated by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS). For analyzing the effect of temperature treatment on corrosion resistance, electrochemical corrosion tests were conducted. It was observed that the polarization curves for carburized samples at 380°C were shifted to lower corrosion current densities. Consequently, lower corrosion rates were achieved for these samples preventing the formation of extensive corrosion over their surfaces comparing with carburized Nickel substrates at 650°C.

Characterization of Fe2O3-CaO-SiO2 Glass Ceramics Prepared by Sol-Gel

2014 ◽  
Vol 624 ◽  
pp. 114-118 ◽  
Author(s):  
Yao Yao Wang ◽  
Bin Li ◽  
Yong Ya Wang
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Optimum Process ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Crystallization Activation Energy ◽  
Treatment Technology ◽  
X Ray ◽  
Heat Treatment Technology

Ferromagnetic glass ceramics with magnetism and biological activity could be used for magnetic induction hyperthermia. In this study Fe2O3-CaO-SiO2glass-ceramics were prepared by sol-gel method. The sample was characterized by X-ray diffraction (XRD) and differential thermal analysis (DTA). The results showed that the major phases of the sample are wollastonite and magnetite and the crystallization activation energy of sample is 189.3KJ/mol, which would provide a theoretical basis for the establishment of the optimum process conditions of heat treatment technology.

Preparation and Characterization of CaF2 Doped Bioglass Ceramics

2011 ◽  
Vol 11 ◽  
pp. 45-66 ◽  
Author(s):  
M.R. Majhi ◽  
R. Pyare ◽  
S.P. Singh
Keyword(s):  
Glass Ceramics ◽  
Melting Process ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Time Period ◽  
Infrared Reflection ◽  
Prepared Glass ◽  
Sbf Solution

Bioglass Ceramics having molar composition 40SiO2-(44-X)CaO-10MgO-6P2O5-XCaF2 (where X = 0 to 8%) were prepared by conventional melting process in an electric globar furnace at 1400±10°C. Controlled crystallizations were carried out to convert the bioglasses to their corresponding ceramics. Nucleation and crystallization regimes were carried out by differential thermal analysis. The crystalline phases termed hydroxy fluoroapatite, akermanite and wollastonite were identified by using x-ray diffraction analysis. The investigation of bioactivity for the prepared glass and glass ceramics was done by infrared absorption and infrared reflection spectra after immersion in simulated body fluid (SBF) for different periods at 37.8°C. Scanning electron microscope (SEM) analysis was carried out to investigate the surface texture. Micrographs show the formation of HCA layer on the surface of the bioglass ceramics samples after 7 days of SBF treatment. The surfaces of the samples were completely covered with irregular and needle-like aggregates of Ca–P layer. The released ions were estimated by atomic absorption spectroscopy. The chemical durability of these materials was determined by pH measurement methods and it was found that pH of the solution increases up from 1 to 7 days. Further, pH decreases with increasing time period, from 15 to 30 days in SBF solution.

Preparation and Characterization of Transparent Oxyfluoride Tellurite Glass-Ceramics Containing CaF2 Nanocrystals

2014 ◽  
Vol 989-994 ◽  
pp. 305-307
Author(s):  
Zhao Xia Hou ◽  
Hang Xin Li ◽  
Shao Hong Wang ◽  
Mei Han Wang ◽  
Xiao Dan Hu
Keyword(s):  
Tellurite Glass ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Melting Method ◽  
X Ray ◽  
Average Size ◽  
Scanning Electron ◽  
Temperature Melting

Transparent oxyfluoride tellurite glass-ceramics containing CaF2 nanocrystals were prepared by high temperature melting method. The glass-ceramics were characterized by Differential scanning calorimetry, X-ray diffraction and scanning electron microscope, respectively. The results showed that the CaF2 nanocrystals were spherical and the average size was found to be 60 nm.

Crystallographic characterization of fluorapatite glass-ceramics synthesized from industrial waste

2017 ◽  
Vol 32 (S2) ◽  
pp. S61-S65 ◽  
Author(s):  
Chee W. Loy ◽  
Khamirul A. Matori ◽  
Norhazlin Zainuddin ◽  
Andrew E. Whitten ◽  
Christine Rehm ◽  
...  
Keyword(s):  
Rice Husk Ash ◽  
Glass Ceramics ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Glass Forming ◽  
Amorphous Silicate ◽  
Silicate Matrices

A series of phase transformations of a novel fluoroaluminosilicate glass forming a range of fluorapatite glass-ceramics on sintering are reported. The sintering process induces formation of fluorapatite, mullite, and anorthite phases within the amorphous silicate matrices of the glass-ceramics. The fluoroaluminosilicate glass, SiO2–Al2O3–P2O5–CaO–CaF2, is prepared from waste materials, such as rice husk ash, pacific oyster shells, and disposable aluminium cans. The thermally induced crystallographic and microstructure evolution of the fluoroaluminosilicate glass towards the fluorapatite glass-ceramics, with applications in dental and bone restoration, are investigated by powder X-ray diffraction and small-angle neutron-scattering techniques.

Thermal Characterization of Neodymium-Barium-Copper Ceramic (NBCo Ceramic) Synthesized from Barium Carbonate

2016 ◽  
Vol 869 ◽  
pp. 74-78
Author(s):  
José Passos Fernandes ◽  
A. Tibola ◽  
M. Lorensetti ◽  
G.W. Duarte ◽  
M.R. Rocha ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Barium Carbonate ◽  
Thermal Characterization ◽  
Neodymium Oxide ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treatment Conditions ◽  
Barium Copper

This work presents a study about thermal properties of a ceramic material based on NdBaCu system sintered with barium carbonate. These specialized ceramics are manufactured under special conditions and due to its unique electrical and thermal properties are frequently used by the electronic industry. Ceramics containing neodymium-barium-copper (NdBaCu) exhibit high conductivity at low temperatures. In this work, the ceramic samples were sintered with different percentage of barium carbonate, cupric and neodymium oxide and were characterized with Termogravimetric Analysis (TGA), Differential Scanning Calorimetric (DSC), Thermal Dilatometric Analysis (TDA) and X-Ray Diffraction Analysis (DRX). The results showed that the electrical conductivity of NdBaCu system is dependent on the calcination temperature. In turn, the complete calcination is dependent on the barium percentage and the thermal treatment conditions.

Crystallization Behavior of Ferroelectric Glass-Ceramics of the Na2O-Nb2O5-Al2O3-SiO2 System Contained TiO2

2009 ◽  
Vol 421-422 ◽  
pp. 189-192 ◽  
Author(s):  
Anuson Niyompan ◽  
Kanita Srisurat ◽  
Rungnapa Tipakontitikul
Keyword(s):  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Volume Fraction ◽  
Treatment Time ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Alumino Silicate ◽  
Quenched Glass

The ferroelectric glass-ceramic of the composition Na2O-Nb2O5-Al2O3-SiO2 was prepared by controlling crystallization of the glass that added with small amount of TiO2. The effect of TiO2 content on crystallization behavior and the dielectric property were determined. X-ray diffraction studied indicated that NaNbO3, NaNbO8 and a compound of alkali alumino silicate composition were readily formed in the as-quenched glass as the product of phase separation. After treatment at 700oC for various times, NaNbO3 volume fraction was found to increase with time. Crystalline size of the NaNbO3 was lower than 300 nm and it was developed with treatment time. Presence of TiO2 had considerably effect on NaNbO3 volume fraction when treatment time shorter than 1.0 h. The dielectric response of the glass-ceramic samples was found to arise from all contributions of crystalline phases and glass matrix responds.

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