Preparation of A14SiC4 by Solid-State Reaction

2011 ◽  
Vol 399-401 ◽  
pp. 817-821
Author(s):  
Xiao Hong Liu ◽  
Hui Wang ◽  
Ling Ke Zeng ◽  
Cheng Ji Deng
Keyword(s):  
Carbon Black ◽  
Raw Materials ◽  
Heating Temperature ◽  
Argon Atmosphere ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Higher Temperature ◽  
Flake Structure ◽  
Scanning Electron

In this paper, A14SiC4 was synthesized by using flint, aluminum and carbon black as raw materials，and they mass ratio was 28:50:22. The samples were fired at 1500°C、1600°C and 1700°C in an argon atmosphere. The phase compositions were determined by X-ray diffraction (XRD), the microstructures were examined by scanning electron microscope (SEM) and the elemental and quantitative compositions were determined by the energy dispersive X-ray spectroscopy (EDX). The results showed that the flint reacted with the carbon black, and produced Al2O3 and SiC firstly; meanwhile Al4C3 as intermediate product formed by the reaction between Al and C. Then a certain Al4C3 reacted with SiC, and produced A14SiC4; most Al4C3 reacted with the Al2O3, and produced Al4O4C at higher temperature. Subsequently, the Al4O4C and the SiC reacted with carbon black, and produced A14SiC4. The formed quantity of A14SiC4 increased as the heating temperature was raised, and crystal structure was the flake structure of 1-2μm thickness and about 10μm length. The formation mechanism of A14SiC4 was also discussed.

Fabrication of MgO-SiC Refractory Composite Powders by High-Silicon Magnesite and Carbon Black Powders

2011 ◽  
Vol 399-401 ◽  
pp. 809-812
Author(s):  
Hong Xi Zhu ◽  
Zhi Jiang Lv ◽  
Cheng Ji Deng ◽  
Wen Jie Yuan
Keyword(s):  
Carbon Black ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
Carbon Black Content ◽  
Composite Powders ◽  
X Ray ◽  
Key Factor ◽  
High Silicon ◽  
Refractory Composite ◽  
Scanning Electron

MgO-SiC refractory powders were prepared by using high-silicon magnesite and carbon black powders as the starting materials calcined at 1550 to 1650 °C, respectively, for 3 hours under argon atmosphere. The phase compositions and microstructure of samples are characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effects of the calcining temperature and the proportion of carbon black on the synthesis of MgO-SiC refractory powders were investigated. The results show that high-silicon magnesite reacts with carbon black to form MgO and SiC as the main phases, and the minor phases include FeSi, Ca3Al2Si3O12 and Mg2SiO4. Carbon black content is the key factor to affect the synthesis of MgO-SiC composite powders.

Synthesis of Ba2B5O9Cl Whiskers via Flux Method

2012 ◽  
Vol 535-537 ◽  
pp. 2567-2570
Author(s):  
Dong Hai Zhu ◽  
Xue Ying Nai ◽  
Qian Qian Song ◽  
Shan Yun ◽  
Yong Xing Zhang ◽  
...  
Keyword(s):  
Sintering Temperature ◽  
Raw Materials ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Flux Method ◽  
High Quality ◽  
X Ray ◽  
Scanning Electron Microcopy ◽  
Scanning Electron

Ba2B5O9Cl whiskers with uniform morphology were synthesized by a simple flux method, using BaCl2•2H2O, H3BO3 as the starting materials, and KCl as the flux. The products were characterized by X-ray diffraction (XRD) and scanning electron microcopy (SEM), and the optimum conditions for preparing high quality Ba2B5O9Cl whiskers were studied. Results show that a sintering temperature around 700 °C, an Ba/B mole ratio of 1:3 and a raw materials to flux mass ratio of 1:2 lead to uniform orthorhombic Ba2B5O9Cl whiskers with a diameter of 0.4-1.0 µm and a length of 10-25 µm.

Synthesis of SiC Nano-Powders by Solid-Vapor Reaction

2006 ◽  
Vol 317-318 ◽  
pp. 211-214
Author(s):  
Seoung Soo Lee ◽  
Jae Won Kim ◽  
Yeon Gil Jung ◽  
Je Hyun Lee ◽  
Jae Hong Yoon ◽  
...  
Keyword(s):  
Carbon Black ◽  
Direct Synthesis ◽  
Morphological Characteristics ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
Qualitative Properties ◽  
Reaction Method ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Silicon carbide (SiC) nano-powders are successfully synthesized by a reaction between carbon nano-powders (carbon black) and SiO gas at 1300°C for 9 hrs in dynamic argon atmosphere (flow rate; 400 cm3 min-1), using the solid-vapor reaction method. The particle size of synthesized SiC nano-powders is below 40 nm and the shape is uniform. Unexpectedly, SiC nano-fibers are also coexisted in the SiC nano-powders. The quantitative and qualitative properties of the SiC nanopowders and nano-fibers are analyzed by scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD). Carbon residuals removed by heating over 700°C in air are estimated by thermogravimetry analysis (TGA). It is found that the SiC nanopowders are easily produced by direct synthesis via the solid-vapor reaction method. The morphological characteristics of the resulting SiC nano-powders are dependent upon the morphology of carbon black used as precursor.

Synthesis of MgAl2O4-SiC-C Refractory Powders by Using Forsterite, Alumina and Carbon Black

2011 ◽  
Vol 399-401 ◽  
pp. 838-841 ◽  
Author(s):  
Hong Juan Duan ◽  
Hong Xi Zhu ◽  
Ping Liang ◽  
Wen Jie Yuan ◽  
Cheng Ji Deng
Keyword(s):  
Carbon Black ◽  
Argon Atmosphere ◽  
Spinel Crystal ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Excess Carbon ◽  
X Ray ◽  
Reducing Atmosphere ◽  
Refractory Composite ◽  
Scanning Electron

In this paper, the synthesis of MgAl2O4-SiC-C refractory composite powders by forsterite, alumina and carbon black was studied. The samples were calcined under reducing atmosphere and argon atmosphere at 1650 °C for 4 hrs respectively. The phase compositions and microstructure of the synthesized powders were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result shows that adding excess carbon can enhance the formation of SiC. The argon atmosphere can promote the carbothermal reaction of forsterite and the growth of spinel crystal.

The Roman Ceramics of Salobrena (Granada-Spain) and their Raw Materials

1992 ◽  
Vol 267 ◽  
Author(s):  
Ana M De Andres ◽  
Isabel MuÑOZ
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Raw Materials ◽  
Third Century ◽  
Western Coast ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Third ◽  
Good Number ◽  
Scanning Electron

ABSTRACTNineteen roman ceramic sherds found near Salobreña (Granada, Spain), in the western coast of the Mediterranean Sea, as well as different ceramic clays from the surroundingsare studied. Both clays and ceramic sherds are characterizad by X-ray diffraction and spectrometry, differential thermal analysis, and scanning electron and optical microscopies. A good number of the ceramic pieces, among which some “Terrae Sigillatae”, have a composition similar to that of the local clays and, thus, have been probably manufactured at Salobreña. Only a few of them have a foreign origin. For most of them, the firing temperature was about 800-850 °C, although some have been produced at 900-1000 °C, and some others at 1000-1100 °C. It is concluded that Salobreña appearsto have been an important settlement just in the third century of the Christian era.

Solvothermal Synthesis of Bi2Se3 Hexagonal Nanosheet Crystals

2011 ◽  
Vol 236-238 ◽  
pp. 1712-1716 ◽  
Author(s):  
Hai Tao Liu ◽  
Jun Dai ◽  
Jia Jia Zhang ◽  
Wei Dong Xiang
Keyword(s):  
Electron Microscope ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Scanning Electron

Bismuth selenide (Bi2Se3) hexagonal nanosheet crystals with uniform size were successfully prepared via a solvothermal method at 160°C for 22 h using bismuth trichloride(BiCl3) and selenium powder(Se) as raw materials, sodium bisulfite(NaHSO3) as a reducing agent, diethylene glycol(DEG) as solvent, and ammonia as pH regulator. Various techniques such as X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) were used to characterize the obtained products. Results show that the as-synthesized samples are pure Bi2Se3 hexagonal nanosheet crystals. A possible growth mechanism for Bi2Se3 hexagonal nanosheet crystals is also discussed based on the experiment.

Structural Evaluation of Ti-22.2Si-11.1B Powders Milled with PCA Addition

2008 ◽  
Vol 591-593 ◽  
pp. 147-153
Author(s):  
Gilbert Silva ◽  
Erika Coaglia Trindade Ramos ◽  
N.S. da Silva ◽  
Alfeu Saraiva Ramos
Keyword(s):  
Electron Microscopy ◽  
Ball Milling ◽  
Ball Mill ◽  
Milling Process ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Evaluation ◽  
Equilibrium Structures ◽  
Scanning Electron

A large amount of the Ti6Si2B compound can be formed by mechanical alloying and subsequent heat treatment from the elemental Ti-22.2at%Si-11.1at%B powder mixture, but the yield powder after ball milling is reduced due to an excessive agglomeration of ductile particles on the balls and vial surfaces. This work reports on the structural evaluation of Ti-22.2at%Si-11.1at%B powders milled with PCA addition, varying its amount between 1 and 2 wt-%. The milling process was carried out in a planetary ball mill under argon atmosphere, and the milled powders were then heated at 1200oC for 1h under Ar atmosphere in order to obtain equilibrium structures. Samples were characterized by X-ray diffraction, scanning electron microscopy, and thermal analysis. Results revealed that the PCA addition reduced the excessive agglomeration during the ball milling of Ti-22.2at-%Si-11.1at-%B powders. After heating at 1200oC for 1h, the Ti5Si3, Ti3O and/or Ti2C phases were preferentially formed in Ti-22.2at%Si-11.1at%B powders milled with PCA addition, and the Ti6Si2B formation was inhibited.

Influence of Fly Ash on Corrosion Resistance of Refractory Forsterite-Spinel Ceramics

2021 ◽  
Vol 325 ◽  
pp. 181-187
Author(s):  
Martin Nguyen ◽  
Radomír Sokolář
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Fly Ash ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Zones ◽  
Refractory Ceramics ◽  
Scanning Electron

This article examines the influence of fly ash on corrosion resistance of refractory forsterite-spinel ceramics by molten iron as a corrosive medium. Fly ash in comparison with alumina were used as raw materials and sources of aluminium oxide for synthesis of forsterite-spinel refractory ceramics. Raw materials were milled, mixed in different ratios into two sets of mixtures and sintered at 1550°C for 2 hours. Samples were characterized by X-ray diffraction analysis and thermal dilatometric analysis. Crucibles were then made from the fired ceramic mixtures and fired together with iron at its melting point of 1535°C for 5 hours. The corrosion resistance was evaluated by scanning electron microscopy on the transition zones between iron and ceramics. Mixtures with increased amount of spinel had higher corrosion resistance and mixtures with fly ash were comparable to mixtures with alumina in terms of corrosion resistance and refractory properties.

Preparation of the System of BaO-MgO-Al2O3-TiO2 Acid-Resistant Fracturing Proppants

2011 ◽  
Vol 399-401 ◽  
pp. 855-859
Author(s):  
Ting Ting Wu ◽  
Bo Lin Wu
Keyword(s):  
Sintering Temperature ◽  
Raw Materials ◽  
Acid Resistance ◽  
Pressureless Sintering ◽  
Alumina Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acid Solubility ◽  
Resistance Performance ◽  
Scanning Electron

In order to improve the acid resistance and reduce the apparent density of fracturing proppants, TiO2 powder added in the system of BaO-MgO-Al2O3 fracturing proppants were prepared by the technique of pressureless sintering. The properties of the samples were investigated by the measurements of acid solubility, X-ray diffraction and scanning electron microscopy. The results show that the acid solubility of alumina matrix fracturing proppants contenting TiO2 of the 4wt% and BaO/MgO with the ratio of 3:7 is 0.15%. It is an important development in acid resistance performance of fracturing proppants research on laboratory. TiO2 is added to the raw materials and then calcine them to ceramics, which can reduces the sintering temperature, promote the densification and improve acid-resistant property of fracturing proppants.

The Effect of Alcoholic Reducing Agent on Morphology and Structure of VO2 (B) Nano-Particles

2011 ◽  
Vol 306-307 ◽  
pp. 1225-1228 ◽  
Author(s):  
Ji Qi ◽  
Chen Niu
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Raw Materials ◽  
Thermal Reduction ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Morphology And Structure ◽  
Properties Of Materials ◽  
Scanning Electron

Vanadium dioxides (VO2) is synthesized by hydrothermal method. In this process,V2O5 powder is used as raw materials,cetyltrimethylammonium bromide (CTAB) is used as template and different alcohols such as methanol, ethanol, propanol and butanol are used as reductants. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to test the properties of VO2 nanoparticles. The results show that VO2(B) nano-particles were succsessfully synthesized under the conditions of thermal reduction temperature 180°C, reaction time 24h and drying temperature 60°C. The variety of alcoholic reducing agents plays an important role in the structure and morphology of the product VO2(B), which relates closly to the electric properties of materials.

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