scholarly journals Diopside Glass-Ceramics for Dental and Biomedical Applications

2014 ◽  
Vol 96 ◽  
pp. 15-20 ◽  
Author(s):  
Jamila Almuhamadi ◽  
Natalia Karpukhina ◽  
Mike Cattell
Keyword(s):  
Molten Glass ◽  
Water Glass ◽  
Biomedical Applications ◽  
Glass Ceramics ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Step Heat Treatment ◽  
Glass Compositions

A series of glass compositions with varying equimolar amounts of Na2O:Al2O3 were designed using Appen factors. High purity batch reagents were ball milled for 30 min and transferred to Pt/Rh crucible and melted in an electric furnace (EHF1700, Lenton, UK) at high temperatures then held for 90 min. The molten glass was poured into a graphite mould, annealed at 50°C below the glass transition temperature for 1h and the remaining glass was quenched into water. Glass frits were crushed and ball milled into powders with different particle sizes. Glass powders (PS<125μm) were heat-treated via two-step heat treatment cycles and air quenched. Experimental glasses and glass-ceramics were characterised using X-Ray Diffraction (XRD), Dilatometry, Scanning Electron Microscopy (SEM) and solid state Nuclear Magnetic Resonance (NMR).

Crystallization of a SiO2-MgO-Al2O3-K2O-Fe2O3-F Glass

2007 ◽  
Vol 336-338 ◽  
pp. 1829-1832 ◽  
Author(s):  
Qing Bo Tian ◽  
Yue Wang ◽  
Xue Tao Yue ◽  
Yan Sheng Yin ◽  
Su Hua Fan
Keyword(s):  
Phase Separation ◽  
Electron Probe ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
Present Glass ◽  
X Ray ◽  
Heat Treated ◽  
Mica Crystal ◽  
Step Heat Treatment ◽  
Scanning Electron

The phase-separation and the crystallization of SiO2-MgO-Al2O3-K2O-Fe2O3-F glass were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe of microanalyzers (EPMA). The results reveal that the varieties and the morphology of crystalline phases formed depend sensitively on the thermal treatment schedules. During the isothermal treatments, the crystalline phases of mica, mica and iron oxide (FeFeO4), and FeFeO4 as major crystals are precipitated in the glass samples heat-treated at 900, 1000 and 1050°C respectively. However, the two-step heat treatment beginning at 900°C for 1h and subsequently followed at 1050°C for 1h leads to the precipitation of mica crystal and no any signs of FeFeO4 crystalline phase is observed. Also the morphology of sample is different from that of the isothermally treated glass at 1050°C, but is similar from that of sample at 900°C. A “worm”-shaped phase-separation is observed in the sample heated at 800°C for 0.5h, which exhibits different morphology from that of droplet- or globule-shape conventionally discerned. EPMA results show that the incorporation of Fe2O3 accelerates accumulation of fluorine element, promoting the phase-separation and the crystallization of the present glass.

Second-Generation Aluminium Extraction Residue Used as Devitrification Aid for Glass-Ceramics

2008 ◽  
Vol 587-588 ◽  
pp. 773-777
Author(s):  
M.C. Ferreira ◽  
Wilson Acchar ◽  
Ana M. Segadães ◽  
Sonia Regina Homem de Mello-Castanho
Keyword(s):  
Second Generation ◽  
Glass Ceramics ◽  
Glass Frit ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Before And After ◽  
Devitrification Process ◽  
Extraction Metallurgy

Brazil has one of the world’s most important Bauxite deposits, the raw material for the aluminium extraction metallurgy. This work is focused on finding a suitable application for the white dross residue (WDR), a second-generation waste material produced during the metal recovery from the slag left after the primary extraction of aluminium from the ore. A commercial lime-silica based glass frit was used, to which WDR additions were made (up to 30 wt.%), aimed at studying the devitrification process of the glasses produced. Such mixtures were melted at temperatures varying from 1100 to 1500°C and the resulting fritted glasses were heat treated at 900°C. The starting materials and the mixtures thereof were characterized before and after thermal treatment by differential thermal analysis, X-ray diffraction and fluorescence, and scanning electron microscopy. The results obtained showed that the WDR is easily incorporated into the glass matrix and causes easy devitrification after short heat treatment periods at low temperature.

Preparation and Characterization of SrO-Fe2O3-FeO-SiO2-B2O3 System Hexaferrites Glass-Ceramics

2012 ◽  
Vol 535-537 ◽  
pp. 855-860
Author(s):  
Jian An Liu ◽  
Mei Mei Zhang ◽  
Xue Na Yang ◽  
Wen He
Keyword(s):  
Glass Ceramics ◽  
Heat Treating ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Mixed Compound ◽  
Anneal Temperature

Based on the SrO-Fe2O3-FeO-SiO2-B2O3 system, the M-type strontium hexaferrites glass ceramics has been prepared through heat treating the melted glass. Using the aqueous solution solvent evaporation and melt method, we obtained the glass precursor of molecular-scale homogenously mixed compound. The precursor was completely melted in a lidded platinum crucible placed in an electric furnace at 1480°C for 1h and then annealed in a furnace at 550°C for 40min. The crystallization of the glass systems with different component has been systematically investigated by using X-ray diffraction (XRD), Transmission Electron Micrographs (TEM) as well as Vibrating Sample Magnetometer (VSM). It is found that Fe3O4 crystal precipitated during naturally cooling the melt from 1480°C to anneal temperature. Moreover, the hexaferrite glass ceramics with the main crystal phase of SrFe12O19 was obtained after heat-treated at 860°C for 2 hours. The magnetic properties of the obtained hexaferrite glass ceramics indicated that the saturation magnetization and the coercivity were 8.1A•m2/kg and 114KA/m, respectively.

scholarly journals X-Ray Diffraction and Raman Spectroscopic Studies of Glasses and Glass-Ceramics Inside the A2O-MoO3-Nb2O5-P2O5 (A= Li, Na) Systems

2010 ◽  
Vol 12 (3,4) ◽  
pp. 207
Author(s):  
H. Bih ◽  
L. Bih ◽  
M.P.F. Graça ◽  
M.A. Valente ◽  
B. Elouadi
Keyword(s):  
Glass Ceramics ◽  
Spectroscopic Studies ◽  
Phosphate Glasses ◽  
Molar Ratio ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Heat Treated ◽  
Quenching Method

<p>Phosphate glasses in the system (50-x)A<sub>2</sub>O-xMoO<sub>3</sub>-10Nb<sub>2</sub>O<sub>5</sub>-40P<sub>2</sub>O<sub>5</sub> (AMo-40), with x=0; 30 and A=Li or Na were prepared by the melt quenching method. The effect in the crystallization behaviour of the glass due to the introduction of MoO<sub>3</sub> in the glass composition and varying the molar ratio between network modifiers and network formers (M/F) was studied. The prepared glasses were heat-treated in air, at 550, 600 and 650 ºC for 4 hours. The structure, of the obtained samples, was studied by differential thermal analysis (DTA), X-ray powder diffraction (XRD), Raman spectroscopy and the morphology by scanning electron microscopy (SEM). It was found that the replacement of Li<sub>2</sub>O or Na<sub>2</sub>O by MoO<sub>3</sub> reduces the number of the crystallised phases. In the lithium-niobiophosphate glasses the presence of MoO<sub>3</sub> promotes the formation of NbOPO<sub>4</sub> and reduces the formation of ortho- and pyro-phosphate phases. The thermal treatments affect the arrangements of the network structure of the AMo-40-glasses.</p>

Influence of Strontium on In Vitro Bioactivity of Heat-Treated Porous Ca-P Ceramics on Titanium for Biomedical Applications

2011 ◽  
Vol 493-494 ◽  
pp. 453-457
Author(s):  
Kuan Chen Kung ◽  
Tzer Min Lee ◽  
Truan Sheng Lui
Keyword(s):  
Body Fluid ◽  
Biomedical Applications ◽  
Clinical Applications ◽  
Apatite Layer ◽  
X Ray Diffraction ◽  
Apatite Phase ◽  
X Ray ◽  
Heat Treated ◽  
Scanning Electron

The bioactivity of materials was evaluated based on the ability to induce a bond-like apatite layer on the surface in simulated body fluid (SBF). The aim of this study was to investigate the coatings containing strontium on bioactivity after heat treatment. After the materials were soaked in SBF for 1 day, precipitates did not form on the surface of heat-treated MAO coating without strontium. The precipitates were observed on surface of heat-treated MAO coatings containing strontium. After 7 days, the surface of heat-treated MAO coatings containing strontium was completely covered with precipitates. The precipitates were found to be composed of fiber structures using scanning electron microscope (SEM). The phase was identified as the apatite phase using thin film X-ray diffraction (TF-XRD). The results show that heat-treated MAO coatings containing strontium can induce the formation of an apatite layer on their surface. All finding in this study indicated that heat-treated MAO coatings containing strontium have good bioactivity for clinical applications.

Temperature-Controlled Devitrification of Oxyfluoride Borate Glasses

2007 ◽  
Vol 130 ◽  
pp. 263-266 ◽  
Author(s):  
Joanna Pisarska ◽  
Tomasz Goryczka ◽  
Wojciech A. Pisarski
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Borate Glasses ◽  
X Ray Diffraction ◽  
Transparent Glass ◽  
X Ray ◽  
Heat Treated ◽  
Before And After ◽  
Controlled Crystallization ◽  
Temperature Controlled

Selected oxyfluoroborate glasses have been investigated before and after heat treatment. Transparent glass-ceramics (TGC) were obtained during controlled crystallization (devitrification). X-ray diffraction studies confirmed that material was partially crystallized. Diffraction lines due to orthorhombic PbF2 phase were identified for heat-treated samples at various temperatures and times. Results were compared to that ones obtained for as-melted glass.

Preparation and Characterization of SrO-Al2O3-Fe2O3-B2O3 System Nano-Ferrimagnetic Glass-Ceramics

2011 ◽  
Vol 415-417 ◽  
pp. 384-389
Author(s):  
Jian An Liu ◽  
Mei Mei Zhang ◽  
Xue Na Yang ◽  
Shu Jiang Liu
Keyword(s):  
Glass Ceramics ◽  
Heat Treating ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Heat Treated ◽  
Intrinsic Coercivity ◽  
Glass Specimen ◽  
Anneal Temperature

Based on the SrO-Al2O3-Fe2O3-B2O3 system, the nano-ferrimagnetic glass ceramics has been prepared through heat treating the melted glass. Using the aqueous solution solvent evaporation and melt method, we firstly obtained the molecular-scale homogenously mixed compound. And thus the glass specimen was produced by naturally cooling the batch melts. The crystallization of the glass systems with diffirent component has been systematically investigated by using X-ray diffraction (XRD), Thermo gravimetric (TG), Differential Thermal Analysis (DTA) as well as Vibrating Sample Magnetometer (VSM). It is found that Fe3O4 crystal precipitated during naturally cooling the melt from 1500°C to anneal temperature. Moreover, the nano-ferromagnetic glass ceramics with the main crystal phase of SrFe12O19 was obtained after heat-treated at 865°C for 2 hours. The size of crystal was 20-50nm. The magnetic properties of the obtained ferromagnetic glass ceramics indicated that the saturation magnetization and the intrinsic coercivity were 32A•m2/kg and 236KA/m, respectively.

Precipitate Phases and Mechanical Properties of Heat-Treated ASTM F 90 Co-Cr-W-Ni Alloy

2014 ◽  
Vol 616 ◽  
pp. 258-262 ◽  
Author(s):  
Kosuke Ueki ◽  
Kyosuke Ueda ◽  
Takayuki Narushima
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Biomedical Applications ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Precipitation Behavior ◽  
X Ray ◽  
Phase Precipitate ◽  
Heat Treated ◽  
Ni Alloy

The precipitation behavior during heat treatment and resulting mechanical properties of ASTM F 90 Co-20Cr-15W-10Ni (mass%) alloys were investigated with regards to their biomedical applications. Heat treatment was conducted at temperatures of 873 to 1623 K, for a holding time of 259.2 ks. The precipitates produced were then electrolytically extracted from the alloys and analyzed by X-ray diffraction (XRD). This revealed that the precipitates formed were an M23X6 type and/or η-phase (i.e., an M6X-M12X type). The M23X6-type precipitate was detected across the entire heat-treatment temperature range; however, the η-phase precipitate was only detected at 1073 to 1473 K, becoming dominant at 1173 to 1373 K. The formation of M23X6 type precipitates at 873 K is shown to improve the mechanical properties of this alloy, whereas the domination by the η-phase precipitate at higher temperatures causes deterioration in the ductility.

Structural and magnetic properties analysis of trivalent Al3+ ions substituted Ni-Zn-Co nano-spinel ferrites

2021 ◽  
Vol 12 (4) ◽  
pp. 045001
Author(s):  
Nusrat Jahan ◽  
J I Khandaker ◽  
H Das ◽  
M N I Khan
Keyword(s):  
Magnetic Properties ◽  
Biomedical Applications ◽  
Single Phase ◽  
Spinel Ferrites ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Optical Bandgaps ◽  
Spinel Structures

Abstract This study explored the structural, morphological, optical, and magnetic properties of Ni0.4Zn0.35Co0.25Fe2−x Al x O4 (0 ≤ x ≤ 0.12) nano-spinel ferrites. Nanocrystalline cubic structure formation and weight loss percentage were determined by thermogravimetric analysis and differential scanning calorimetry (TGA - DSC). Single-phase cubic spinel structures with Fd3m space group of synthesized samples were confirmed by Rietveld refinement X-ray diffraction (XRD) data. The particle sizes were found to be in the range of 6.7 nm–5.25 nm, and agglomeration occurs inside the ferrite samples. The atomic planes and strong crystallinity were detected through SAED images. The characteristic peaks of the Raman spectra identified the bonding between the cations and anions in the sub-lattices. The optical bandgaps (E g ) were found to be in the range of 2.1 eV–2.52 eV. S-shape hysteresis (M-H) loops identified the superparamagnetic nature of the nano-samples. The studies’ outcomes indicated the applicability for biomedical applications of these nano samples.

The Influence of Heat Treatment on the Structure and Microstructure of Ti-15Mo-xNb System Alloys for Biomedical Applications

2014 ◽  
Vol 783-786 ◽  
pp. 1255-1260 ◽  
Author(s):  
José Roberto Severino Martins ◽  
Carlos Roberto Grandini
Keyword(s):  
Heat Treatment ◽  
Biomedical Applications ◽  
Elasticity Modulus ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Class ◽  
Β Phase ◽  
Heat Treated ◽  
Beta Structure ◽  
Structure And Microstructure

The Ti-15Mo-xNb system integrates a new class of titanium alloys without the presence of aluminum and vanadium, which exhibit cytotoxicity, and that have low elasticity modulus values (below 100 GPa). This occurs because these alloys have a beta structure, which is very attractive for use as biomaterials. In addition, Brazil has about 90% of the world’s resources of niobium, which is very important economically. It strategically invests in research on the development and processing of alloys containing this element. In this paper, a study of the influence of heat treatments on the structure and microstructure of the alloys of a Ti-15Mo-xNb system is presented. The results showed grain grown with heat treatment and elongated and irregular grains after lamination due to this processing. After quenching, there were no changes in the microstructure in relation to heat-treated and laminated conditions. These results corroborate the x-ray diffraction results, which showed the predominance of the β phase.

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