Preparation of in situ grown silicon carbide whiskers onto graphite for application in Al2O3-C refractories

2018 ◽  
Vol 44 (12) ◽  
pp. 13944-13950 ◽  
Author(s):  
Zhenglong Liu ◽  
Chengji Deng ◽  
Chao Yu ◽  
Xing Wang ◽  
Jun Ding ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Silicon Carbide Whiskers

Boron Nitride Coatings on Silicon Carbide Whiskers

1996 ◽  
Vol 458 ◽  
Author(s):  
Steven Brown ◽  
Richard Partch
Keyword(s):  
Silicon Carbide ◽  
Boron Nitride ◽  
Porous Carbon ◽  
Carbon Layer ◽  
Silicon Oxynitride ◽  
Sodium Borate ◽  
Time Control ◽  
Silicon Carbide Whiskers ◽  
Novel Processing

ABSTRACTBoron nitride thin films have been produced on silicon carbide whiskers (SiCw) by a novel processing method. A polydivinylbenzene (PDVB) coating was formed in situ on the whisker surface which was subsequently thermally degraded creating a highly porous carbon layer. The total available pore volume of the carbon layer/ SiCw system (SiCwC) was varied by controlling the quantity of PDVB adsorbed. Next, anhydrous sodium borate was mixed with the SiCwC, and upon heating, the precursor melted and absorbed into the porous carbon layer followed by nitridation with anhydrous ammonia. Under certain reaction conditions, silicon oxynitride was also produced as a sublayer. The amount of the latter can be controlled by varying the reaction temperature and time. Control over the thickness of the BN film was achieved by varying the amount of the carbonized polymer layer in proportion to the quantity of sodium borate.

Crystallization of In-Situ SiC-Mullite Composites from Multicomponent Alumina-Silica Gels

1990 ◽  
Vol 180 ◽  
Author(s):  
S. Jagota ◽  
A. Parvizi-Majidi
Keyword(s):  
Silicon Carbide ◽  
Glassy Phase ◽  
Silica Gels ◽  
Processing Conditions ◽  
In Situ Composites ◽  
Silicon Carbide Whiskers ◽  
Alumina Gels

ABSTRACTSilica and alumina gels were mixed to make a hybrid of a mullite precursor gel and a silicon carbide precursor gel. The crystallization of these above 1400 °C, to form in-situ composites of silicon carbide whiskers in a matrix of mullite, cristobalite and a glassy phase, was studied for different processing conditions.

A discussion of the chemical mixing process for in situ preparation of silicon carbide whiskers in silicon nitride powder

1988 ◽  
Vol 3 (3) ◽  
pp. 538-544 ◽  
Author(s):  
Shigehiko Yamada ◽  
Shiushichi Kimura ◽  
Yasuda Eiichi ◽  
Yasuhiro Tanabe ◽  
Yuuichi Asami
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Room Temperature ◽  
Bending Strength ◽  
In Situ Preparation ◽  
Silicon Carbide Whiskers ◽  
Silicon Nitride Powder ◽  
Physical Mixing ◽  
Chemical Mixing

To produce a homogeneous composite of silicon carbide whiskers in a silicon nitride matrix, the whiskers were formed in situ. The resulting bulk density was higher than that obtained by a physical mixing of the components using a dispersion procedure. Bending strength at room temperature of the in situ formed composite was about the same as that for the physically mixed composite when the small amount of carbon remaining in the in situ formed composite was removed.

Reordering and Crystallization of Silicon Carbide Amorphized by Neutron Irradiation

2000 ◽  
Vol 650 ◽  
Author(s):  
Lance L. Snead ◽  
Martin Balden
Keyword(s):  
Thin Film ◽  
Silicon Carbide ◽  
Crystallization Kinetics ◽  
Neutron Irradiation ◽  
Onset Temperature ◽  
Kinetics Of Crystallization ◽  
Crystallization Onset Temperature ◽  
Crystallization Onset ◽  
Kinetics Of

ABSTRACTDensification and crystallization kinetics of bulk SiC amorphized by neutron irradiation is studied. The temperature of crystallization onset of this highly pure, fully amorphous bulk SiC was found to be between 875-885°C and crystallization is nearly complete by 950°C. In-situ TEM imaging confirms the onset of crystallization, though thin-film effects apparently alter the kinetics of crystallization above this temperature. It requires >1125°C for complete crystallization of the TEM foil. Annealing at temperatures between the irradiation and crystallization onset temperature is seen to cause significant densification attributed to a relaxation, or reordering, of the as-amorphized structure.

scholarly journals Synergy Effects in Electromagnetic Properties of Phosphate Ceramics with Silicon Carbide Whiskers and Carbon Nanotubes

2019 ◽  
Vol 9 (20) ◽  
pp. 4388 ◽  
Author(s):  
Artyom Plyushch ◽  
Jan Macutkevič ◽  
Polina Kuzhir ◽  
Aliaksei Sokal ◽  
Konstantin Lapko ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Silicon Carbide ◽  
Wide Frequency Range ◽  
Electromagnetic Properties ◽  
Aluminium Phosphate ◽  
Silicon Carbide Whiskers ◽  
Synergy Effects ◽  
Multi Walled Carbon Nanotubes ◽  
The Difference ◽  
Walled Carbon Nanotubes

Hybrid composite materials based on an aluminium phosphate matrix with silicon carbide whiskers and multi-walled carbon nanotubes were studied in a wide frequency range (20 Hz to 36 GHz). It was demonstrated, that the addition of the silicon carbide whiskers enhances the dielectric permittivity and conductivity. This was explained by the difference in tunnelling parameters. Hybrid ceramics with nanotubes and whiskers also exhibits substantially improved electromagnetic shielding properties. The hybrid ceramics with 10 wt. % silicon carbide whiskers and a 1 mm thick 1.5 wt. % carbon nanotube layer, show higher than 50% absorption of electromagnetic radiation.

scholarly journals Simultaneous effects of rice husk silica and silicon carbide whiskers on the mechanical properties and morphology of sodium geopolymer

2020 ◽  
Vol 54 (29) ◽  
pp. 4611-4620 ◽  
Author(s):  
Akm Samsur Rahman ◽  
Chirag Shah ◽  
Nikhil Gupta
Keyword(s):  
Silicon Carbide ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Silica Nanoparticles ◽  
Rice Husk ◽  
Silicon Carbide Whiskers ◽  
Short Beam ◽  
Spherical Silica ◽  
Beam Shear ◽  
Strength Improvement

The current research is focused on developing a geopolymer binder using rice husk ash–derived silica nanoparticles. Four types of rice husks were collected directly from various rice fields of Bangladesh in order to evaluate the pozzolanic activity and compatibility of the derived rice husk ashes with precursors of sodium-based geopolymers. Silicon carbide whiskers were introduced into sodium-based geopolymers in order to evaluate the response of silicon carbide whiskers to the interfacial bonding and strength of sodium-based geopolymers along with rice husk ashes. Compression, flexural and short beam shear tests were performed to investigate the synergistic effect of rice husk ashes–derived silica and commercially available silicon carbide whiskers. Results show that rice husk ashes–derived spherical silica nanoparticles reduced nano-porosity of the geopolymers by ∼20% and doubled the compressive strength. The simultaneous additions of rice husk ashes and silicon carbide whiskers resulted in flexural strength improvement by ∼27% and ∼97%, respectively. The increase in compressive strength due to the inclusion of silica nanoparticles is related to the reduction in porosity. The increase in flexural strength due to simultaneous inclusion of silica and silicon carbide whiskers suggest that silica particles are compatible with the metakaolin-based geopolymers, which is effective in consolidation. Finally, microscopy suggest that silicon carbide whiskers are effective in increasing bridged network and crack resistance.

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