Submicron Boron Carbide Synthesis through Rapid Carbothermal Reduction

Boron Carbide is a ceramic material of technological application due to its extreme hardness and high chemical and thermal stability. The effect of synthesized boron carbide addition on pressureless sintering and hot-pressing of a commercial B4C was investigated. B4C synthesized by carbothermal reduction using carbon black as carbon source was mixtured in 10, 30 and 50 wt% to a commercial B4C. Powder mixtures were compacted into pellets and sintered by pressureless sintering at 2050 °C/30min Samples were compared to a pure commercial B4C and characterization results have not showed great differences. Relative densities of as-sintered materials exceed 93% of theoretical for all compositions and microhardness Hv of ∼ 32 GPa was obtained.

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Kinetics of Carbothermal Reduction Synthesis of Boron Carbide

Journal of the American Ceramic Society ◽

10.1111/j.1151-2916.1992.tb05604.x ◽

1992 ◽

Vol 75 (9) ◽

pp. 2509-2514 ◽

Cited By ~ 67

Author(s):

Alan W. Weimer ◽

William G. Moore ◽

Raymond P. Roach ◽

James E. Hitt ◽

Ravindra S. Dixit ◽

...

Keyword(s):

Boron Carbide ◽

Carbothermal Reduction ◽

Kinetics Of

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Effect of Molecular Structure of Polyols with Different Molecular Characteristics on Synthesis of Boron Carbide Powder

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.534.61 ◽

2013 ◽

Vol 534 ◽

pp. 61-65 ◽

Cited By ~ 15

Author(s):

Masaki Kakiage ◽

Naoki Tahara ◽

Yusuke Tominaga ◽

Satomi Yanagidani ◽

Ikuo Yanase ◽

...

Keyword(s):

Molecular Structure ◽

Thermal Decomposition ◽

Boron Carbide ◽

Carbothermal Reduction ◽

Poly Vinyl Alcohol ◽

Molecular Characteristics ◽

Carbide Powder ◽

Excess Carbon ◽

Condensed Product ◽

Crystalline Boron

Crystalline boron carbide (B4C) powder was synthesized by the carbothermal reduction of condensed products formed from boric acid (H3BO3) and polyols with different molecular characteristics, i.e., glycerin, mannitol, and poly (vinyl alcohol) (PVA). The effect of the molecular structure of the polyol on the thermal decomposition conditions and the obtained morphology of the B4C powder was discussed in this study. The thermal decomposition in air of each condensed product was performed before the carbothermal reduction in order to eliminate the excess carbon, where the decomposition conditions varied with the type of polyol. Crystalline B4C powder with less residual free carbon was synthesized from the thermally decomposed products by heating at 1250 °C for 5 h in an Ar flow. The thermal decomposition conditions and the particle size of the obtained B4C powder reflected the molecular characteristics of the polyols.

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Processing factors influencing the free carbon contents in boron carbide powder by rapid carbothermal reduction

Diamond and Related Materials ◽

10.1016/j.diamond.2015.11.005 ◽

2016 ◽

Vol 61 ◽

pp. 14-20 ◽

Cited By ~ 10

Author(s):

Yong Gao ◽

Anthony Etzold ◽

Tyler Munhollon ◽

William Rafaniello ◽

Richard Haber

Keyword(s):

Boron Carbide ◽

Carbothermal Reduction ◽

Free Carbon ◽

Carbide Powder ◽

Factors Influencing ◽

Processing Factors

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Nanocrys Talline Boron Carbide Powder Synthesized Via Carbothermal Reduction Reaction

Advances in Ceramic Armor XI - Ceramic Engineering and Science Proceedings ◽

10.1002/9781119211549.ch6 ◽

2015 ◽

pp. 63-74

Author(s):

Said M. El-Sheikh ◽

Yasser M. Z. Ahmed ◽

Emad M. M. Ewais ◽

Asmaa Abd-El-Baset Abd Allah ◽

Said Anwar

Keyword(s):

Boron Carbide ◽

Carbothermal Reduction ◽

Reduction Reaction ◽

Carbide Powder ◽

Carbothermal Reduction Reaction

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Synthesis of Nanocrystalline Boron Carbide by Direct Microwave Carbothermal Reduction of Boric Acid

Journal of Nanomaterials ◽

10.1155/2017/3983468 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 8

Author(s):

Rodolfo F. K. Gunnewiek ◽

Pollyane M. Souto ◽

Ruth H. G. A. Kiminami

Keyword(s):

Boron Carbide ◽

Carbothermal Reduction ◽

Average Length ◽

Chemical Properties ◽

Microwave Assisted Synthesis ◽

Synthesis Of Nanoparticles ◽

Elongated Nanoparticles ◽

Physical And Chemical ◽

Total Reaction Time ◽

And Chemical Properties

The excellent physical and chemical properties of boron carbide make it suitable for many applications. However, its synthesis requires a large amount of energy and is time-consuming. Microwave carbothermal reduction is a fast technique for producing well crystallized equiaxial boron carbide nanoparticles of about 50 nm and very few amounts of elongated nanoparticles were also synthesized. They presented an average length of 82 nm and a high aspect ratio (5.5). The total reaction time was only 20 minutes, which disfavor the growing process, leading to the synthesis of nanoparticles. Microwave-assisted synthesis leaded to producing boron-rich boron carbide. Increasing the forward power increases the boron content and enhances the efficiency of the reaction, resulting in better crystallized boron carbide.

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Surface Properties and Morphology of Boron Carbide Nanopowders Obtained by Lyophilization of Saccharide Precursors

Materials ◽

10.3390/ma14123419 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3419

Author(s):

Dawid Kozień ◽

Piotr Jeleń ◽

Joanna Stępień ◽

Zbigniew Olejniczak ◽

Maciej Sitarz ◽

...

Keyword(s):

Aqueous Solutions ◽

Boron Carbide ◽

Boric Acid ◽

Carbothermal Reduction ◽

Molar Ratio ◽

Argon Flow ◽

Heat Treated ◽

Freeze Dried ◽

Organic Precursors ◽

High Temperature Reactions

The powders of boron carbide are usually synthesized by the carbothermal reduction of boron oxide. As an alternative to high-temperature reactions, the development of the carbothermal reduction of organic precursors to produce B4C is receiving considerable interest. The aim of this work was to compare two methods of preparing different saccharide precursors mixed with boric acid with a molar ratio of boron to carbon of 1:9 for the synthesis of B4C. In the first method, aqueous solutions of saccharides and boric acid were dried overnight at 90 °C and pyrolyzed at 850 °C for 1 h under argon flow. In the second method, aqueous solutions of different saccharides and boric acid were freeze-dried and prepared in the same way as in the first method. Precursors from both methods were heat-treated at temperatures of 1300 to 1700 °C. The amount of boron carbide in the powders depends on the saccharides, the temperature of synthesis, and the method of precursor preparation.

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