Study of self propagating high temperature synthesis of β silicon carbide materials

1997 ◽  
Vol 52 (2) ◽  
pp. 35
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

scholarly journals Self-Propagating High-Temperature Synthesis of Silicon Carbide and Silicon Nitride Nanopowders Composition using Sodium Azide and Halides

2013 ◽  
Vol 16 (1) ◽  
pp. 41 ◽  
Author(s):  
Yu.V. Titova ◽  
A.P. Amosov ◽  
G.V. Bichurov ◽  
D.A. Maidan
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Silicon Nitride ◽  
Combustion Synthesis ◽  
Sodium Azide ◽  
Average Particle Size ◽  
Average Particle ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Working Volume

<p>Regularities of self-propagating high-temperature synthesis (SHS) or combustion synthesis (CS) by using “silicon – sodium azide – ammonium hexafluorosilicate – carbon – aluminum” powder mixture in the nitrogen atmosphere were investigated. The thermodynamic analysis of the combustion synthesis was performed. Experimental investigation of the combustion process: the measurement of linear rates of the combustion front propagation and the maximum combustion temperatures was conducted in a laboratory reactor with working volume 4.5 liters. The influence of the components ratio in the initial mixture on the combustion temperature, combustion rate and composition of reaction product was studied. The phase composition of the product synthesized was determined with an X-ray  diffractometer. It was disclosed that the SHS product consists of the composition (mixture) of silicon carbide nanopowder with silicon nitride whiskers and a final halide. Investigation of surface topography and morphology of the product particles was carried out with a scanning electron microscope. Optimal mixture for the synthesis of nanoscale composition based on silicon carbide was determined: “14Si+6NaN<sub>3</sub>+(NH<sub>4</sub>)<sub>2</sub>SiF<sub>6</sub>+15C+Al”. In this case, the SHS product consists of four phases: silicon carbide (β-SiC) – 48.57 wt.%, α-silicon nitride (<em>α</em>-Si<sub>3</sub>N<sub>4</sub>) – 27.04 wt.%, β-silicon nitride (β-Si<sub>3</sub>N<sub>4</sub>) – 5.83 wt.%, and sodium hexafluoroaluminate (Na<sub>3</sub>AlF<sub>6</sub>) – 18.56 wt.%. The average particle size of the composition was in the range of 70–130 nm. It was shown that the composition of the silicon carbide with silicon nitride and the final halide Na<sub>3</sub>AlF<sub>6</sub> playing a role a flux can be used as a modifier of castable aluminum alloys and as a reinforcing phase of aluminomatrix composites.</p>

Self-propagating high-temperature synthesis of silicon carbide nanopowders

2013 ◽  
Vol 449 (1) ◽  
pp. 41-43 ◽  
Author(s):  
D. O. Moskovskikh ◽  
A. S. Mukasyan ◽  
A. S. Rogachev
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

Self-Propagating High-Temperature Synthesis of Silicon Carbide Nanofibers

2020 ◽  
Vol 61 (6) ◽  
pp. 675-679
Author(s):  
V. V. Zakorzhevsky ◽  
V. E. Loryan ◽  
T. G. Akopdzhanyan
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

PECULIARITIES OF THE SYNTHESIS OF HIGH-TEMPERATURE CERAMICS TASI2–SIC, REINFORCED IN SITU BY DISCRETE SILICON CARBIDE NANOFIBERS

2018 ◽  
pp. 72-76
Author(s):  
S. Vorotilo ◽  
E. D. Polozova ◽  
E. A. Levashov
Keyword(s):  
Fracture Toughness ◽  
Silicon Carbide ◽  
High Temperature ◽  
Relative Density ◽  
Hot Pressing ◽  
Temperature Synthesis ◽  
Similar Composition ◽  
High Temperature Synthesis ◽  
Sic Ceramic

The possibility of the increase of the properties of ceramics in the TaSi2–SiC system via the reinforcement by the SiC nanofibers formed in situ in the combustion wave has been studied. For the formation of nanofibers as well as for increase of the exothermicity of the reaction mixtures, energetic additive PTFE (C2F4) was used. Using the method of self-propagating high-temperature synthesis of the mechanically activated mixtures, 70%TaSi2+30%SiC ceramic was produced, with SiC present as the round-shaped grains and as nanofibers. Ceramic specimens sintered by hot pressing were characterized by relative density up to 98 %, hardness 19,0–19,2 GPa and fracture toughness 7,5–7,8 MPa·m1/2, which is noticeably above the fracture toughness of the ceramic with similar composition produced without the PTFE additions.

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