Preparation and Characterization of Na2O-Y2O3-P2O5-SiO2 Transparent Glass Ceramics

2018 ◽  
Vol 281 ◽  
pp. 692-698 ◽  
Author(s):  
Meng Jie Zhao ◽  
Xiang Yu Zou ◽  
Qin Lei Wei ◽  
Shuo Meng ◽  
Hong Bo Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Refractive Index ◽  
Glass Ceramic ◽  
Visible Region ◽  
Glass Ceramics ◽  
Scanning Calorimetry ◽  
Transparent Glass ◽  
Diffraction Patterns ◽  
The Impact ◽  
Precursor Glass

Transparent glass ceramics containing Na3.6Y1.8(PO4)3 crystals were successfully synthesized using high temperature melting quenching and subsequent heat treatment of the precursor glass with a composition 15Na2CO3-3Y2O3-45SiO2-31H3BO3- 5.4P2O5-0.6Sb2O3 (mol%). The impact of heat treatment is investigated in detail. The glass sample was tested by differential scanning calorimetry analysis to determine the heat treatment system. The ideal heat-treated condition is at 650°C for 2 h. The structure and morphology properties were systematically analyzed by recording X-ray diffraction patterns and scanning electron microscopy images, which indicate that Na3.6Y1.8(PO4)3 crystal were precipitated homogeneously among the glass matrix. The microstructural of precursor glass and glass ceramic were compared by analyzing FTIR spectra, indicating the formation of phosphate groups in glass ceramic. The refractive index of glass ceramics samples were measured. In the visible region, the transmittance of glass ceramics is up to 85%. Moreover, the relationship between the refractive index of the sample and the transmittance is discussed.

Research on Processing Conditions of CBS Transparent Glass-Ceramics

2013 ◽  
Vol 873 ◽  
pp. 733-736
Author(s):  
Yi Min Wang ◽  
Hong Bo Zhang ◽  
Chun Hui Su ◽  
Qin Lei Wei
Keyword(s):  
Heat Treatment ◽  
Luminescence Property ◽  
Room Temperature ◽  
Glass Ceramics ◽  
Nucleating Agent ◽  
Processing Conditions ◽  
Transparent Glass ◽  
Melting Method ◽  
Heat Treatment Regime ◽  
Precursor Glass

On the basis of experimental verification, the optimum processing conditions of CaO-B2O3-SiO2(CBS) system transparent glass-ceramics were obtained. Composition of main raw powders (wt%) was:CaO 38%,SiO240%,B2O312%.The precursor glass was prepared by melting method and annealed at 560°C for 2h and cooled to room temperature at a speed of 5°C/min.The best nucleating agent is P2O5. The appropriate heat treatment regime to precursor glass was determined to be 2h at 600°C for nucleation and 3h at 780°C for crystallizition.Under this condition,the transmittion of glass-ceramics at the range of visable light is 72% in average and Sm3+keep good luminescence property doped in this host material.

scholarly journals Tailoring the Glass Composition to Increase the Thermal Stability without Impacting the Crystallization Behavior of Oxyfluorophosphate Glass

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 148-159
Author(s):  
Nirajan Ojha ◽  
Iuliia Dmitrieva ◽  
Wilfried Blanc ◽  
Laeticia Petit
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Glass Ceramic ◽  
Glass Composition ◽  
Glass Ceramics ◽  
Glass Network ◽  
Thermally Stable ◽  
Heat Treated ◽  
The Impact ◽  
Thermal Stability Of

Even though the (75 NaPO3-25 CaF2) (in mol%) glass can be heat-treated into transparent glass-ceramic with Er3+ doped CaF2 crystals precipitating in the volume of the glass during heat-treatment, this glass was found to be a poor glass former, limiting its use as upconverter under 975 nm pumping. In this study, the impact of the glass composition on the thermal, optical and structural properties of the glass was investigated in order to understand how the glass composition can be tailored for the development of thermally stable upconverter glass-based material. The addition of MgO, Fe2O3 and Al2O3 in the NaPO3-CaF2 glass system increases the thermal stability of glass due to the depolymerization of the glass network. However, the changes in the glass composition also impacted on the nucleation and growth process. Indeed, CaF2 and other crystals were found in the newly developed glasses after heat-treatment leading to glass-ceramics with lower intensity of upconversion than the (75 NaPO3-25 CaF2) glass-ceramic used as a reference. Glasses were also prepared with different concentrations of Er2O3 and ErF3. These glasses were found to be promising as not only are they thermally stable, but they also exhibit green and red emission with high intensity under 975 nm pumping due to Er3+ clustering.

Investigations of lithium-chloro-borate glass-ceramic and its elastic properties

2010 ◽  
Vol 88 (8) ◽  
pp. 569-574 ◽  
Author(s):  
Y. Shivaprakash ◽  
R. V. Anavekar
Keyword(s):  
Heat Treatment ◽  
Elastic Properties ◽  
Glass Ceramic ◽  
Treatment Time ◽  
Poisson Ratio ◽  
Glass Ceramics ◽  
Heat Treatment Time ◽  
Shear Moduli ◽  
Ir Studies ◽  
Precursor Glass

Elastic properties and microstructural studies of 0.3Li2O-0.2LiCl-0.5B2O3 glass-ceramics have been carried out for a precursor glass prepared using the rapid melt quenching technique. Quenched glasses were heat treated (by three step process) at 150 °C for 2, 4, 6, and 8 h. Scanning electron microscopy and X-ray diffraction studies clearly indicate gradual growth of different phases in the glass matrix with increasing time of heat-treatment. IR studies reveal the structural modification in the network as the precursor glass transformed into glass-ceramic. Elastic properties have been measured by performing ultrasonic wave velocity measurements at a frequency of 10 MHz. Longitudinal and shear moduli of the samples tend to increase with heat-treatment time. However, the bulk modulus is almost insensitive to heat treatment. The Debye temperature was found to increase, and the Poisson ratio lies in the range 0.2–0.3 (typical for covalently bonded networks) with an increase in heat-treatment time.

Preparation and Characterization of Superionic Conductive Li2O-Al2O3-La2O3-TiO2-P2O5 Glass-Ceramics

2012 ◽  
Vol 509 ◽  
pp. 314-320 ◽  
Author(s):  
Hong Ping Chen ◽  
Hai Zheng Tao ◽  
Qi De Wu ◽  
Xiu Jian Zhao
Keyword(s):  
Heat Treatment ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Lithium Ion ◽  
Treatment Temperature ◽  
Total Conductivity ◽  
Scanning Calorimetry ◽  
Structural Morphology ◽  
Heat Treated ◽  
Different Temperatures

Li2O-Al2O3(La2O3)-TiO2-P2O5 glass-ceramics were fabricated through heat-treatment of the original glass. The differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical workstation were employed to study the structural, morphology and electrical properties of the samples heat-treated at different temperatures. The results showed that: the glass-ceramics consist of the dominating LiTi2(PO4)3 phases, trifle AlPO4, TiO2 and unknown phases. With the heat-treatment temperature increasing from 700 °C to 1100 °C, the structure of glass-ceramic become denser and grain grew, lithium ion conductivity increased quickly and subsequent cut down gradually. While the specimen was obtained by crystallization at 900 °C for 12 h, the total conductivity of glass-ceramic material come up to the maximum (5.85 ×10-4 S•cm-1) at 25 °C. This inorganic solid electrolyte has a potential application in lithium batteries or other devices.

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.

scholarly journals Utilization of discarded foundry sand (DFS) and inorganic waste from cellulose and paper industry for the manufacture of glass-ceramic materials

Cerâmica ◽  
2020 ◽  
Vol 66 (380) ◽  
pp. 413-420
Author(s):  
L. M. S. e Silva ◽  
R. S. Magalhães ◽  
W. C. Macedo ◽  
G. T. A. Santos ◽  
A. E. S. Albas ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Raw Materials ◽  
Paper Industry ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Foundry Sand ◽  
X Ray ◽  
Glass Ceramic Materials

Abstract Recycling has been pointed out as an alternative to the disposal of waste materials in industrial landfills. In the present study, the transformation of residues (discarded foundry sand - DFS, grits, and lime mud) in glass-ceramic materials is shown. The glasses were obtained by the melting/cooling method. The precursor materials, glasses, and glass-ceramics were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA). The glassy materials were milled, pelleted, and thermally treated at the crystallization temperatures given by DSC data to obtain the glass-ceramics (885, 961, and 1090 ºC). The main formed phases were cristobalite, α-wollastonite (parawollastonite), and β-wollastonite (pseudowollastonite). The glass-ceramics showed very low water absorption and apparent porosity (0.26 to 0.88 wt% and 0.66 to 1.77 vol%, respectively). The results confirmed that the studied residues can be used as raw materials for the manufacture of vitreous and glass-ceramic materials.

Preparation by solution mixing and characterization of condensation type poly(dimethyl siloxane)/graphene nanoplatelets composites

2021 ◽  
pp. 002199832110558
Author(s):  
Panayiotis Ketikis ◽  
Efthimios Damopoulos ◽  
Georgios Pilatos ◽  
Panagiotis Klonos ◽  
Apostolos Kyritsis ◽  
...  
Keyword(s):  
Graphene Nanoplatelets ◽  
Matrix Composites ◽  
Dielectric Relaxation Spectroscopy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Melting Temperatures ◽  
Dimethyl Siloxane ◽  
Diffraction Patterns ◽  
The Impact

The impact of the incorporation of graphene nanoplatelets (GN) on the properties of hydroxyl-terminated poly(dimethylsiloxane) (PDMS) matrices was investigated. The composites were prepared by solution mixing, using tetrahydrofuran (THF) as a solvent. Brookfield viscosimetry, implemented during the vulcanization process, revealed that GN increases the viscosity of the system, compared to pristine PDMS, proportionally to its concentration. X-ray diffraction patterns suggested an efficient dispersion of GN in the polysiloxane matrix. The D and G bands ratio (ID/IG) calculation, based on RAMAN spectra of GN/PDMS specimens, revealed more defects in graphene nanoplatelets when incorporated in the PDMS matrix. By differential scanning calorimetry (DSC), a marginal increase in crystallization, glass transition and melting temperatures of PDMS in GN/PDMS composites was observed. Improvement of the thermal stability of LMW PDMS composites, especially for higher GN concentrations (3 and 5 phr), was noticed by thermogravimetric analysis (TGA). Additionally, GN enhanced the tensile strength of composites, up to 73% for the 3 phr GN/LMW PDMS composite. A significant increase in the elongation at break was recorded, whereas no effect on the modulus of elasticity was recorded. The decrease in toluene-swelling, for the LMW PDMS matrix composites, was attributed to the increase in the tortuosity path because of the efficient dispersion of GN. A decrease in oxygen permeability of 55–65% and 44–58% was measured in membranes made of PDMS composites containing 0.5 phr and 1 phr GN, respectively. Dielectric relaxation spectroscopy (DRS) measurements recorded a significant increase in the conductivity of the higher graphene content composites.

scholarly journals Spectroscopic Properties of Erbium-Doped Oxyfluoride Phospho-Tellurite Glass and Transparent Glass-Ceramic Containing BaF2 Nanocrystals

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3429 ◽  
Author(s):  
Magdalena Lesniak ◽  
Jacek Zmojda ◽  
Marcin Kochanowicz ◽  
Piotr Miluski ◽  
Agata Baranowska ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Tellurite Glass ◽  
Thermal Structure ◽  
Spectroscopic Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Erbium Doped ◽  
Quenching Method ◽  
Erbium Trifluoride ◽  
Precursor Glass

The ErF3-doped oxyfluoride phospho-tellurite glasses in the (40-x) TeO2-10P2O5-45 (BaF2-ZnF2) -5Na2O-xErF3 system (where x = 0.25, 0.50, 0.75, 1.00, and 1.25 mol%) have been prepared by the conventional melt-quenching method. The effect of erbium trifluoride addition on thermal, structure, and spectroscopic properties of oxyfluoride phospho-tellurite precursor glass was studied by differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), and Raman spectroscopy as well as emission measurements, respectively. The DSC curves were used to investigate characteristic temperatures and thermal stability of the precursor glass doped with varying content of ErF3. FTIR and Raman spectra were introduced to characterize the evolution of structure and phonon energy of the glasses. It was found that the addition of ErF3 up to 1.25 mol% into the chemical composition of phospho-tellurite precursor glass enhanced 2.7 µm emission and upconversion. By controlled heat-treatment process of the host glass doped with the highest content of erbium trifluoride (1.25 mol%), transparent erbium-doped phospho-tellurite glass-ceramic (GC) was obtained. X-ray diffraction analysis confirmed the presence of BaF2 nanocrystals with the average 16 nm diameter in a glass matrix. Moreover, MIR, NIR, and UC emissions of the glass-ceramic were discussed in detail and compared to the spectroscopic properties of the glass doped with 1.25 mol% of ErF3 (the base glass).

scholarly journals Impact of Morphology and Microstructure on the Mechanical Properties of Ge-As-Pb-Se Glass Ceramics

2020 ◽  
Vol 10 (8) ◽  
pp. 2836 ◽  
Author(s):  
Rashi Sharma ◽  
Rebecca Welch ◽  
Myungkoo Kang ◽  
Claudia Goncalves ◽  
Cesar Blanco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Vickers Hardness ◽  
Glass Ceramic ◽  
Volume Fraction ◽  
Glass Ceramics ◽  
Post Heat Treatment ◽  
Base Glass ◽  
Parent Glass ◽  
Crystal Phases

The impact of base glass morphology and post heat-treatment protocol on the mechanical properties (Vickers hardness and Young’s modulus) of a multi-component glass-ceramic was examined. Two parent chalcogenide glasses with identical composition but varying morphology (homogeneous and phase separated) were evaluated for their mechanical properties following identical thermal processing to induce crystallization. The nucleation and growth rates of the starting materials were compared for the two glasses, and the resulting crystal phases and phase fractions formed through heat treatment were quantified and related to measured mechanical properties of the glass ceramics. The presence of a Pb-rich amorphous phase with a higher crystal formation tendency in the phase-separated parent glass significantly impacted the volume fraction of the crystal phases formed after heat-treatment. Pb-rich cubic crystal phases were found to be dominant in the resulting glass ceramic, yielding a minor enhancement of the material’s mechanical properties. This was found to be less than a more moderate enhancement of mechanical properties due to the formation of the dominant needle-like As2Se3 crystallites resulting from heat treatment of the homogeneous, commercially melted parent glass. The greater enhancement of both Vickers hardness and modulus in this glass ceramic attributable to the high-volume fraction of anisotropic As2Se3 crystallites in the post heat-treated commercial melt highlights the important role base glass morphology can play on post heat-treatment microstructure.

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