scholarly journals Low-Temperature Molten Salt Synthesis and the Characterisation of Submicron-Sized Al8B4C7 Powder

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 70
Author(s):  
Cheng Liu ◽  
Xueyin Liu ◽  
Zhaoping Hou ◽  
Quanli Jia ◽  
Benjun Cheng ◽  
...  
Keyword(s):  
Low Temperature ◽  
Molten Salt ◽  
Raw Materials ◽  
Reaction Medium ◽  
Thermal Reduction ◽  
Molten Salt Synthesis ◽  
Synthesis Process ◽  
Direct Reaction ◽  
Liquid Reaction ◽  
Reduction Methods

Submicron-sized (~200 nm) aluminium boron carbide (Al8B4C7) particles were synthesised from Al, B4C and carbon black raw materials in a molten NaCl-based salt at a relatively low temperature. The effects of the salt type/assembly and the firing temperature on the synthesis process were examined, and the relevant reaction mechanisms discussed. The molten salt played an important role in the Al8B4C7 formation process. By using a combined salt of 95%NaCl + 5%NaF, an effective liquid reaction medium was formed, greatly facilitating the Al8B4C7 formation. As a result, essentially phase-pure Al8B4C7 was obtained after 6 h of firing at 1250 °C. This temperature was 350–550 °C lower than that required by the conventional direct reaction and thermal reduction methods.

Synthesis and Reaction Mechanism of Ti3SiC2 by Molten Salt Method from Ti-Si-Fe Alloy

2018 ◽  
Vol 768 ◽  
pp. 159-166 ◽  
Author(s):  
Jin Hua Zhang ◽  
Si Xiong ◽  
Chang Ming Ke ◽  
Hong Dan Wu ◽  
Xin Rong Lei
Keyword(s):  
Electron Microscope ◽  
Molten Salt ◽  
Raw Materials ◽  
Synthesis Method ◽  
Molten Salt Synthesis ◽  
Synthesis Process ◽  
Molten Salt Method ◽  
Synthetic Temperature ◽  
Chloride Salts ◽  
Titanium Silicon

Titanium silicon carbide (Ti3SiC2) were obtained by molten salt synthesis method using the Ti-Si-Fe alloy extracted from high titania blast furnace slag and natural graphite as the raw materials. The phase composition, microscopic structure of the products were characterized by powder X-ray diffraction, scanning electron microscope and transmission electron microscope. The influence of firing temperature and chloride salts species on the phase and morphology of the products were investigated. The results indicated that the synthetic temperature of Ti3SiC2 by molten salt synthesis method was about 100 °C, which was lower than that without molten salts. The “dissolution-precipitation” mechanism governed the overall molten salt synthesis process. The lamellar Ti3(Si,Al)C2 crystal growth obeyed by a two-dimensional ledge growth mechanism.

scholarly journals Morphology control of SrBi2Nb2O9 prepared by a modified chemical method

2019 ◽  
Vol 51 (4) ◽  
pp. 353-361
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  
Keyword(s):  
Molten Salt ◽  
Reaction Medium ◽  
Precipitation Method ◽  
Molten Salt Synthesis ◽  
Synthesis Process ◽  
Strontium Nitrate ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Co Precipitation

SrBi2NbO9 compounds were prepared through three methods: oxalate co-precipitation, molten salt synthesis and polymerizable complex. The effect of the molecular precursor route has also been investigated. For oxalate co-precipitation method, a solution obtained from acid oxalate, niobium oxide, bismuth nitrate and strontium nitrate are precipitated by ammoniac solution. Then, the precipitated sample is calcined at 1100?C. A methanol-citric acid solution of solution of NbCl5, ethylene glycol, bismuth and strontium nitrates were used as precursors. A black powder ash was crystallized by heat-treating at 1100?C. Molten salt technique using oxides and carbonate as starting materials and NaCl and KCl to form a reaction medium. The formation temperature was at 1110?C. Multiple characterizations mainly X-ray diffraction, Fourier transformed infrared spectroscopy and scanning electron microscopy (SEM) measurements have provided to validate the structural feature. Careful, X-ray diffraction analysis showed the presence of two-layered Aurivillius structure. The crystallite size is discussed by Scherrer and Williamson-Hall approaches. SEM images of SrBi2NbO9 ceramics showed plate-like, polygonal and structureless morphologies obtained at different synthesis conditions. Whatever the synthesis process, there is no change on the band of infrared spectra.

Preparing high surface area porous carbon from biomass by carbonization in a molten salt medium

RSC Advances ◽  
2015 ◽  
Vol 5 (92) ◽  
pp. 75728-75734 ◽  
Author(s):  
Huishan Shang ◽  
Yanjie Lu ◽  
Feng Zhao ◽  
Cong Chao ◽  
Bing Zhang ◽  
...  
Keyword(s):  
Molten Salt ◽  
Surface Area ◽  
Porous Carbon ◽  
High Surface ◽  
High Surface Area ◽  
Molten Salt Synthesis ◽  
Synthesis Process ◽  
Salt Medium ◽  
Peanut Shells

Peanut shells were transformed into porous carbon with a high surface area through a simple ZnCl2-molten salt synthesis process.

Molten-salt nitridation synthesis of cubic ZrN nanopowders at low temperature via magnesium thermal reduction

2018 ◽  
Vol 44 (7) ◽  
pp. 8710-8715 ◽  
Author(s):  
Yang Chen ◽  
Chengji Deng ◽  
Chao Yu ◽  
Jun Ding ◽  
Hongxi Zhu
Keyword(s):  
Low Temperature ◽  
Molten Salt ◽  
Thermal Reduction ◽  
Magnesium Thermal Reduction

scholarly journals Microwave-Assisted Molten-Salt Facile Synthesis of Chromium Carbide (Cr3C2) Coatings on the Diamond Particles

2019 ◽  
Vol 38 (2019) ◽  
pp. 370-379 ◽  
Author(s):  
Lei Xu ◽  
Chenlong Wei ◽  
Wei Li ◽  
Libo Zhang ◽  
Jinhui Peng
Keyword(s):  
Molten Salt ◽  
Chromium Carbide ◽  
Coating Thickness ◽  
Raw Materials ◽  
Heating Temperature ◽  
Molten Salt Synthesis ◽  
Positive Role ◽  
Temperature Range ◽  
Microwave Assisted ◽  
Diamond Particles

AbstractChromium carbide (Cr3C2) coatings on the diamond were fabricated using the mixtures of molten salt of NaCl and BaCl2, powders of metallic chromium and diamond as raw materials in the temperature range of 750–900 °C by the microwave-assisted molten-salt synthesis. The morphology, microstructure and phase composition of the surface layer were characterized by Scanning Electron Microscopy, Energy-dispersive Spectrometry and X-ray diffraction. The results show that the surface of the diamond particles could be coated with Cr, forming a uniform and continuous Cr3C2-coated layer. The coatings thickness on the diamond can be controlled by adjusting the heating temperature and time. The coating thickness expanded from 0.73 to 2.30 µm when the temperature was increased from 750 °C to 900 °C, and increasing rapidly during the temperature range of 800  °C–850  °C, the coating thickness expanded from 1.30 to 2.80 µm when the holding time was increased from 0.5 h to 4 h. The results illustrate that the microwave-assisted molten salt synthesis plays a positive role in chromium coatings on the diamond, offering a potent method for the surface metallization of diamond.

scholarly journals Low-Temperature High-Efficiency Preparation of TiB2 Micro-Platelets via Boro/Carbothermal Reduction in Microwave Heated Molten Salt

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2555 ◽  
Author(s):  
Jie Liu ◽  
Jianghao Liu ◽  
Yuan Zeng ◽  
Haijun Zhang ◽  
Zhi Li
Keyword(s):  
Low Temperature ◽  
Molten Salt ◽  
Carbothermal Reduction ◽  
High Efficiency ◽  
Raw Materials ◽  
Synergistic Effects ◽  
Synthesis Conditions ◽  
Crystalline Nature ◽  
Boron Carbide B4c ◽  
Hexagonal Platelet

A molten-salt and microwave co-facilitated boro/carbothermal reduction methodology was developed for low temperature high-efficiency synthesis of TiB2 powders. By using relatively inexpensive titanium oxide (TiO2), boron carbide (B4C) and amorphous carbon (C) as raw materials, single-phase TiB2 powders were prepared after 60 min at as low as 1150 °C or after only 20 min at 1200 °C. Such synthesis conditions were remarkably milder than those required by the conventional reduction routes using the identical reducing agent. As-synthesized TiB2 powders exhibited single-crystalline nature and well-grown hexagonal-platelet-like morphology. The achievement of low temperature high-efficiency preparation of high-quality TiB2 microplatelets in the present work was mainly attributable to the synergistic effects of molten-salt medium and microwave heating.

Effects of Starting Materials on Molten Salt Synthesis of Bi4Ti3O12

2008 ◽  
Vol 55-57 ◽  
pp. 165-168
Author(s):  
Paisan Setasuwon ◽  
S. Kijamnajsak
Keyword(s):  
Molten Salt ◽  
Grain Growth ◽  
Grain Orientation ◽  
Crystal Size ◽  
Raw Materials ◽  
Piezoelectric Materials ◽  
Molten Salt Synthesis ◽  
Chloride Salt ◽  
Templated Grain Growth

Na0.5Bi0.5TiO3 is one of the potential candidates for non-lead piezoelectric materials to replace existing lead-based ones. Properties of BNT could be enhanced by reactive templated grain growth (RTGG) technique through induction of grain orientation with crystals of Bi4Ti3O12. Controlling the size of Bi4Ti3O12 crystals during the synthesis with molten salt is a major factor in optimizing RTGG. It was found that molten salt synthesis of Bi4Ti3O12 crystals with NaCl-KCl yielded larger particles, compared with Na2SO4-3K2SO4. Varying the proportion of chloride salt did not produce noticeable changes in crystal size. Bi4Ti3O12 crystals were significantly affected by raw materials treatment. Non-milling of starting powders could approximately double the crystal size

Molten Salt Synthesis of Ni0.5Zn0.5Fe2O4 Ferrites

2012 ◽  
Vol 512-515 ◽  
pp. 1420-1423
Author(s):  
Hong Tao Jiang ◽  
Xiu Feng Wang ◽  
Li Li Wang ◽  
Cheng Long Yu
Keyword(s):  
Molten Salt ◽  
Raw Materials ◽  
Initial Permeability ◽  
Holding Time ◽  
Molten Salt Synthesis ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Text Structures ◽  
Average Grain Size ◽  
Zno Powders

In this paper, Ni0.5Zn0.5Fe2O4ferrite ceramics were produced with Ni0.5Zn0.5Fe2O4powders prepared by reaction in a molten salt using Fe2O3, NiO and ZnO powders as raw materials. Ni-Zn powders were characterized by X-ray diffraction (XRD). Density and shrinkage in diameter of Ni0.5Zn0.5Fe2O4ceramics were measured. MicroSubscript text structures were observed using field emission scanning electron microscopy (FESEM), and magnetic properties were examined by HP4291B impedance analyzer. XRD pattern indicated that the powders synthesized at 900°C for 1h were pure spinel Ni0.5Zn0.5Fe2O4phase. Via the measurement of density and shrink in diameter, optimal temperature was 1200°C and holding time was 2h, which was in accord with the results concluded from micrographs. FESEM images illustrated that the average grain size increased with increasing holding time, which followed the Ostwald liquid growth mechanism. At lower frequencies, the initial permeability (μi) increased from 86.65 to 183.48 with increasing holding time, while the threshold frequency decreased from 13.3MHz to 8.52MHz, which implied the initial permeability (μi) variation complied with the Snoek law to some extent.

Molten salt synthesis of YAG:Ce3+ phosphors from oxide raw materials

2014 ◽  
Vol 40 (3) ◽  
pp. 5067-5071 ◽  
Author(s):  
Lin Gan ◽  
Zhi-Yong Mao ◽  
Fang-Fang Xu ◽  
Ying-Chun Zhu ◽  
Xue-Jian Liu
Keyword(s):  
Molten Salt ◽  
Raw Materials ◽  
Molten Salt Synthesis
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