scholarly journals Effect of crystallization heat treatment on the microstructure of niobium-doped fluorapatite glass-ceramics

2012 ◽  
Vol 100B (5) ◽  
pp. 1198-1205 ◽  
Author(s):  
I. Denry ◽  
J. A. Holloway ◽  
P. K. Gupta
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Niobium Doped ◽  
Crystallization Heat

Manufacture of the Glass-Ceramics from the Lead-Zinc Tailings by Sintering

2014 ◽  
Vol 955-959 ◽  
pp. 2818-2823
Author(s):  
Xue Lian Ou ◽  
Yan Ping Guo ◽  
Gao Hui Zhong ◽  
Bao Qing Li ◽  
Ying Chen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Crystalline Phase ◽  
Bending Strength ◽  
Orthogonal Experiment ◽  
Glass Ceramics ◽  
Nucleating Agent ◽  
Weight Losses ◽  
Glass Aggregate ◽  
Lead Zinc ◽  
Crystallization Heat

The glass-ceramics of CaO-Al2O3-SiO2system were prepared by sintering using lead-zinc tailings. Orthogonal experiment was carried out to optimize the ratio of lead-zinc tailings, chemical composition of basic-glass and other chemical materials in the system. Crystallization heat treatment conditions were confirmed by the differential thermal analysis (DTA) curve of glass aggregate. Crystalline phase, crystal morphology and mechanical property of the glass-ceramics samples were studied by means of X-ray diffraction (XRD), scanning electron microscope (SEM), hardness and bending strength test. The results indicated that the optimized ratio of the samples was lead-zinc tailings 25%, quartz 46.63%, calcite 21.05%, Al2O310.19% and nucleating agent TiO21%. The optimized crystallization heat treatment was that basic glass was first heated to 800 °C at 10 °C/min, then 800°C-900 °C at 5 °C/min and held still at 900 °C for 2 h. After that, the basic glass was heated to 1230 °C at 1-1.5 °C/min,held for 1h. At last, the glass-ceramics was obtained after the cooling-down of the system. The main crystalline phase of microcrystal glass-ceramics are diopside. The hardness and bending strength were 9.14 GPa and 213.6 MPa, respectively. The glass-ceramics had excellent chemical durability in acid and alkali solution, with weight losses of 0.17% and 0.68%, respectively.

Pre-crystallization heat treatment and infrared luminescence enhancement in Ni2+-doped transparent glass-ceramics

2019 ◽  
Vol 515 ◽  
pp. 42-49 ◽  
Author(s):  
N.V. Golubev ◽  
E.S. Ignat'eva ◽  
V.M. Mashinsky ◽  
Е.О. Kozlova ◽  
V.N. Sigaev ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Luminescence Enhancement ◽  
Transparent Glass ◽  
Infrared Luminescence ◽  
Crystallization Heat

Crystallization and dielectric properties of SrO–BaO–Nb2O5–GeO2 tungsten–bronze glass–ceramics

2001 ◽  
Vol 16 (7) ◽  
pp. 2057-2063 ◽  
Author(s):  
Jiin-Jyh Shyu ◽  
Hsin-Wei Peng
Keyword(s):  
Heat Treatment ◽  
Dielectric Properties ◽  
Tungsten Bronze ◽  
Glass Ceramics ◽  
Dielectric Behavior ◽  
Dendritic Morphology ◽  
Dielectric Constants ◽  
Two Stage ◽  
Tetragonal Tungsten Bronze ◽  
Stage Heat Treatment

The crystallization and dielectric properties of SrO–BaO–Nb2O5–GeO2 glass–ceramics were investigated. One- and two-stage heat-treatment methods were used to convert the parent glass to glass–ceramics. Strontium barium niobate (SBN) with a tetragonal tungsten-bronze structure formed as the major crystalline phase. When the crystallizing temperature/time was increased, the secondary crystalline BaGe2O5 phase coexisted with SBN. BaGe2O5 formed as a surface layer grown from the surface into the interior of the sample. The dendritic morphology of SBN crystals was examined. The glass–ceramics crystallized by two-stage heat treatment have higher dielectric constants than those crystallized by one-stage heat treatment. The highest dielectric constant that was obtained in the present glass–ceramics was 320. The glass–ceramics showed relaxor-type dielectric behavior.

scholarly journals Optimization of heat treatment of glass-ceramics made from blast furnace slag

2020 ◽  
Vol 39 (1) ◽  
pp. 539-544
Author(s):  
Yi-Ci Wang ◽  
Pei-Jun Liu ◽  
Guo-Ping Luo ◽  
Zhe Liu ◽  
Peng-Fei Cao
Keyword(s):  
Heat Treatment ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Orthogonal Experiment ◽  
Glass Ceramics ◽  
Iron And Steel ◽  
Heat Treatment Regime ◽  
Main Crystalline Phase ◽  
Optimum Heat ◽  
Furnace Slag

AbstractCaO–MgO–Al2O3–SiO2 glass-ceramics with diopside as the main crystalline phase were prepared by melting blast furnace slag obtained from Baotou Iron and Steel Company. The effect of heat treatment on the crystallization behavior of glass-ceramics, containing a large proportion of melted blast furnace slag, was studied by means of differential thermal analysis and scanning electron microscopy. The optimum heat-treatment regime was obtained by orthogonal experimental results for glass-ceramics in which blast furnace slag comprised 70% of the composition and 1% Cr2O3 and 4% TiO2 were used as nucleating agents. The nucleation temperature was 750°C for 2.5 h and the crystallization temperature was 930°C for 1 h. Under this regime, the performance of the glass-ceramic was better than that of other groups in the orthogonal experiment.

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.

Lead titanate glass-ceramics derived from a silicate-based melt

2005 ◽  
Vol 20 (5) ◽  
pp. 1316-1323 ◽  
Author(s):  
P. Sooksaen ◽  
I.M. Reaney ◽  
D.C. Sinclair
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Crystal Size ◽  
Finite Size ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Finite Size Effects ◽  
Peak Broadening ◽  
Permittivity Measurements ◽  
Nano Size

Glass composition 39PbO–1BaO–25TiO2–9.8Al2O3–24.2SiO2–1B2O3 (mol%) crystallized on heat treatment at ≥600 °C to form glass-ceramics whose majority phase was PbTiO3 (PT). At 600 °C, nano-size PT crystals (∼20–50 nm) with a c/a ratio of 1.000(1) were observed, but as heat-treatment temperature increased to 1000 °C, the crystal size and c/a ratio increased to ∼1.2 μm and 1.056(4), respectively. Permittivity measurements as a function of temperature revealed a broad peak at ∼400 °C associated with the nanocrystalline PT crystals, but it sharpened and increased in temperature as heat treatment temperature increased to 1000 °C. The causes of peak broadening and shift of Tc are believed to be due to either clamping of PT crystals by glass matrix, finite size effects due to their intrinsically small size, or the incorporation of dopant impurities such as Al, Si, or Ba ions in the PT phase.

Preparation of Glass-Ceramics Using Molybdenum Tailings

2011 ◽  
Vol 284-286 ◽  
pp. 1431-1434 ◽  
Author(s):  
Jin Rui Zhang ◽  
Ru Wang
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crystalline Phase ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
The Other ◽  
Raw Material ◽  
Physical Chemical ◽  
Nucleation Agents

In order to utilization the molybdenum tailings which be deposited in large quantities. Test used it to prepare glass-ceramics as main raw material, TiO2 as nucleation agents and CaO-Al2O3-SiO2 system and wollastonite as the principal crystalline phase. Heat treatment system of glass-ceramics was based on the differential thermal analysis. The crystalline phase, microstructure and characteristics of glass-ceramics were analysis by XRD, SEM and physical, chemical properties test. The result shows that the performance of glass-ceramics was superior to the other types of building decoration stone.

Microstructure and Crystallization of MAS Glass-Ceramics Containing Alkali Oxides

2010 ◽  
Vol 177 ◽  
pp. 437-440
Author(s):  
Zhuo Hao Xiao ◽  
Jian Er Zhou ◽  
Yong Qing Wang
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Melt Quenching ◽  
Base Glass ◽  
Sio2 Glass ◽  
Sio2 System ◽  
Treatment Conditions ◽  
Strength Tests ◽  
Alkali Oxides ◽  
Regular Network

MgO-Al2O3-SiO2 glass-ceramics containing 4.0w% alkali oxides were prepared by conven- tional melt quenching technique. The effects of heat treatment conditions on crystal types, microstructure and break strength of the glass-ceramics were studied by DSC, XRD, SEM and break strength tests. The main crystallization phases of this glass system are β-quartz (Li2-2xMgxAl2Si3O10) and β-Spodumene, no cordierite phase found. The glass-ceramics possessed a regular network-shaped microstructure feature formed by pyroxene crystals. With the increase of temperature, the β-Quartz around pyroxene crystals converted into β-spodumene and the regular network-shaped microstructure feature getting weaker and disappeared. The average break strength of the glass-ceramics containing no cordierite crystals based on MgO2-Al2O3-SiO2 system is about 150MPa, which is much high than the base glass.

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