scholarly journals Effect of calcium fluoride on sintering behavior of SiO2-CaO-Na2O-MgO glass-ceramic system

2012 ◽  
Vol 6 (3) ◽  
pp. 159-164 ◽  
Author(s):  
Bahman Mirhadi ◽  
Behzad Mehdikhani
Keyword(s):  
Calcium Fluoride ◽  
Glass Ceramics ◽  
Partial Replacement ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Ceramic System ◽  
Crystallization Peak ◽  
X Ray ◽  
Treatment Processes ◽  
Caf2 Content

The crystallization characteristics of glasses based on the SiO2-CaO-Na2O-MgO (SCNM) system containing calcium fluoride (CaF2) have been investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The partial replacement of CaO by CaF2 in the studied glass-ceramics led to the development of different crystalline phase assemblages, including wollastonite and diopside using various heat-treatment processes. With the increase of CaF2 content, the crystallization temperature of the glass and the strength of the crystallization peak temperature decreases. Addition of CaF2 up to 6.0 mol%, as expected, improved the sinterability. This sample reached to maximum density by sintering at 950 ?C.

Influences of Fe2O3 Doping on the Crystallization of SiO2-Al2O3-MgO-K2O-ZrO2-F Glass-Ceramics

2009 ◽  
Vol 79-82 ◽  
pp. 1503-1506 ◽  
Author(s):  
Qing Bo Tian ◽  
Li Na Xu ◽  
Li Yang ◽  
Yan Sheng Yin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elevated Temperatures ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Crystallization Peak ◽  
X Ray ◽  
Microstructural Morphology ◽  
Microscopy Techniques ◽  
Scanning Electron

The influences of Fe2O3 doping on crystallization characteristics and microstructural morphology in the SiO2-Al2O3-MgO-K2O-ZrO2-F glass were investigated by using differential scanning calorimeter, X-ray diffraction and scanning electron microscopy techniques. The results indicate that the addtions of Fe2O3 shift the crystallization peaks to higher temperatures and the crystallization peaks increases in magnitude and the gap values between two crystallization peak temperatures boarden with the increment of Fe2O3 contents.The star-shaped crystals of cordietite by dendritic-manner growths are homogeneously precipitated in the rusidual glass. The mica phases, which are precipitated at interdendritic cordietite phases and formed the plate shapes at the elevated temperatures. The mica crystals grow at the expense of cordietite phases and finally form the composites of mica/cordietite uniformly distributed.

Surface Crystallization of ZnO-Al2O3-SiO2 Glass

2007 ◽  
Vol 280-283 ◽  
pp. 1655-1658
Author(s):  
Xiao Dong Li ◽  
Jie Mo Tian ◽  
Chen Wang ◽  
Li Min Dong
Keyword(s):  
Heat Treatment ◽  
Treatment Time ◽  
Glass Ceramics ◽  
Surface Crystallization ◽  
X Ray Diffraction ◽  
Crystalline Layer ◽  
Surface Conditions ◽  
X Ray ◽  
Treatment Processes ◽  
Electronic Microscope

ZnO-Al2O3-SiO2 glasses with different surface conditions were surface crystallized by different heat treatment process. Differential thermal analysis (DTA), X-ray diffraction analysis (XRD) and scanning electronic microscope (SEM) were used to investigate the crystallization behavior of glasses, the crystalline components and microstructure of the as-got glass-ceramics. According to the DTA results, different heat treatment processes of surface crystallization on the glass were adopted. The SEM results show that surface conditions of glasses are important for the surface crystallization, and the thickness of surface crystalline layer increases with heat treatment time.

The Effect of SiO2, TiO2, and B2O3 on the Crystallization of Glass-Ceramics Glaze Properties

2016 ◽  
Vol 690 ◽  
pp. 206-211 ◽  
Author(s):  
Lada Punsukumtana ◽  
Sansanee Rugthaicharoencheep ◽  
Usuma Naknikham ◽  
Netnapha Suphanam
Keyword(s):  
Vickers Hardness ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
High Hardness ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Glaze ◽  
Industry Applications ◽  
Firing History

The feasibility of developing glass-ceramic glaze in the system KNaO-CaO-MgO-ZnO with a variation in the composition of SiO2, TiO2, and B2O3 was studied. The SiO2, TiO2, and B2O3 were varied in the amount of 2.25-1.50, 0.001-0.10, and 0-0.1 molar equivalents respectively. The samples were one fired at 1180°C or double fired by reheat at the crystallization temperature for 10 minutes. The gloss, sintering behavior, phase, microstucture, and hardness, and were examined by glossmeter, side-view hot stage microscope, X-ray diffraction, SEM, and Vickers hardness respectively. The results showed the importance effect of SiO2, TiO2, and B2O3 on the glaze crystallization ability and its properties. At the fix value of Al2O3 at 0.24 molar equivalents and with the 0.001-0.10 molar equivalents of TiO2, lower the SiO2 content to 1.50 molar equivalents increased the glaze crystallization potential. An increase in the B2O3 to 0.1 molar equivalents suppressed the potential of glaze crystallization. The phases of samples were amorphous or composed of silicon dioxide and diopside as the main phases depending on the glaze composition and the firing history. In this study, the glaze appearances transparent to opaque and varied from gloss to matte with the specular gloss values between 23-100 GU. All samples appeared to have high Vickers hardness value in the range of 553-644. The crystallization decreased the gloss but increased the hardness value for the 2.25 molar equivalents SiO2 glaze. Finally, a composition with high hardness and high gloss was identified and its properties was also presented. These results suggested the limitation and the potential for applying this glass-ceramic glaze system to industry applications.

Sintering Behavior of LZS Glass-Ceramics

2012 ◽  
Vol 727-728 ◽  
pp. 1028-1033 ◽  
Author(s):  
Jaime Domingos Teixeira ◽  
Antonio Pedro Novaes de Oliveira ◽  
Lourival Boehs ◽  
Francielly Roussenq Cesconeto ◽  
Cristina Siligardi ◽  
...  
Keyword(s):  
Glass Powder ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Thermal Shrinkage ◽  
Sintering Behavior ◽  
Maximum Hardness ◽  
X Ray Diffraction ◽  
Time Intervals ◽  
X Ray ◽  
Powder Compacts

Sintering and crystallization behaviors of a LZS glass-powder were investigated by means of thermal shrinkage, differential thermal analysis, X-ray diffraction as well as density and mechanical properties measurements. The melted glass, 9.56Li2O.22.36ZrO2.68.08SiO2(wt%) first was cast into water to provide a frit for milling. The milled glass powder (mean particle size 5.0 µm) was then uniaxially pressed at 100 MPa and the obtained samples were isothermally sintered in the 800-950°C temperature range in air for appropriated time intervals (15-120 min). Sintering was found to start at about 640°C and crystallization took place just after completion of sintering and was almost complete at 920°C. The glass powder compacts crystallized into lithium and zircon silicates so that glass-ceramics with relative densities between 84 and 99% were obtained reaching maximum hardness and bending strength values of 8 ± 0.5 GPa and 214 ± 20 MPa, respectively.

Effect of Nucleating Agents on Crystallization Glass Ceramics Produced from Nickel Slag

2010 ◽  
Vol 105-106 ◽  
pp. 773-777
Author(s):  
Yali Wang ◽  
Lin Jun Wang ◽  
Ming Sheng Ma ◽  
Wen Ni ◽  
Yun Sheng Feng
Keyword(s):  
Crystallization Kinetic ◽  
Glass Ceramics ◽  
Differential Scanning Calorimetric ◽  
Nucleating Agents ◽  
X Ray Diffraction ◽  
Mineral Phase ◽  
X Ray ◽  
Dsc Measurements ◽  
Treatment Processes ◽  
Equation Analysis

A laboratory preparation process of glass ceramics from nickel slag was introduced. The controlled heat treatment processes were carried out on the basis of differential scanning calorimetric (DSC) measurements. Mineral phase and microstructure of crystallized glass were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The modified Kissinger equation was employed to investigate the crystallization kinetic parameters, activation energy E and the k(Tp). The Avrami exponent, n, was calculated by Augis-Bennett equation. Analysis indicated that the glass with 10%TiO2 added was peril to crystallize, of a large value of k(Tp), its k(Tp) is 0.244, E is 522.76kJ/mol and n is 3.42. The crystal phase is diopside.

scholarly journals Crystallization Behavior and Microstructure of Bio Glass-Ceramic System

2013 ◽  
Vol 19 ◽  
pp. 58-68 ◽  
Author(s):  
Behzad Mehdikhani ◽  
Gholam Hossein Borhani
Keyword(s):  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Glass Ceramics ◽  
Al2o3 Content ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Molar Percent ◽  
Glass Compositions

The effects of Al2O3 on the crystallization behavior of glass compositions in the Na2O-CaO-SiO2 system were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Effect of Al2O3 content on the mechanical, density, phase formation and microstructures of Na2O-CaO–P2O5–Al2O3-SiO2 glass ceramics were studied. Thermal parameters of each glass were studied by DTA. The density of the glass ceramic samples was measured by Archimedes’ method. It was found that the glass–ceramic containing 2.0 molar percent Al2O3 had desirable sintering behavior and reached to an acceptable density. Phase investigation and micro structural study were performed by XRD and SEM, respectively.

Crystallization of Cordierite-Based Glass-Ceramics Adding with Fe2O3-TiO2

2007 ◽  
Vol 336-338 ◽  
pp. 1856-1858 ◽  
Author(s):  
Shu Ming Wang ◽  
Kai Ming Liang ◽  
Le Fu Mei ◽  
Feng Zhou
Keyword(s):  
Glass Ceramics ◽  
Crystallization Behaviour ◽  
Primary Field ◽  
X Ray Diffraction ◽  
Crystallization Peak ◽  
Parent Glass ◽  
X Ray ◽  
Cordierite Glass ◽  
Radiation Material ◽  
Mixture Additives

The effect of Fe2O3-TiO2 mixture additives on the crystallization behaviour of a parent glass with composition located in the primary field of cordierite within the MgO-Al2O3-SiO2 system has been examined. The crystallization behaviour of the glass was determined by differential thermal analysis (DTA) and X-ray diffraction (XRD). The microstructure was characterized by scanning electron microscopy (SEM). The results show that additives of Fe2O3-TiO2 can lower the temperature of the crystallization peak (Tp) and promote crystallization of the parent glass. By controlled thermal treatment, the main crystal phase obtained was Fe2+substituted α-cordierite. The approach outlined in this paper to obtain heterogeneous ion substituted cordierite glass-ceramics is useful to develop infrared radiation material with good properties.

Physical and Mechanical Properties of Cement Paste Were Used Partially with Fly Ash and Kaolin Waste

2017 ◽  
Vol 866 ◽  
pp. 199-203
Author(s):  
Chidchanok Chainej ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Room Temperature ◽  
Physical And Mechanical Properties ◽  
Partial Replacement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lime Water ◽  
Diffraction Patterns ◽  
Iron Mold

The aims of this research were study the microstructures and mechanical properties for partial replacement of cement with Fly ash (FA) and kaolin waste (KW). Ordinary Portland cement were partially replaced with FA and KW in the range of 25-35% and 10-25% by weight of cement powder. The kaolin waste was ground for 180 minutes before using. The specimen was packing into an iron mold which sample size of 5×5×5 cm3. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the incubation lime water bath at age of 3 days. After that the specimens were dry cured with plastic wrap at age of 3, 7, 14 and 28 days. After that the compounds were examined by x-ray diffraction patterns (XRD) and the microstructures were examined by scanning electron microscopy (SEM). The compressive strength was then investigated.

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
Dsc Measurements ◽  
Transmission Window

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

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.

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