Self-propagating high-temperature synthesis of the SiC

1986 ◽  
Vol 1 (2) ◽  
pp. 275-279 ◽  
Author(s):  
Osamu Yamada ◽  
Yoshinari Miyamoto ◽  
Mitsue Koizumi
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Exothermic Reaction ◽  
Experimental System ◽  
Ignition Process ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Effect Of Particle Size ◽  
Constituent Elements ◽  
Heat Released

Self-propagating high-temperature synthesis (SHS), also called combustion synthesis, is useful for fabricating numerous ceramics. In the case of SiC, heat released from the exothermic reaction is not sufficient to completely convert the mixed reactants of constituent elements into SiC in the usual nonadiabatic experimental system. This disadvantage could be overcome by a new ignition process called, the “direct passing method of electric current.” By using this method, stoichiometric fine SiC powder could be obtained rapidly and efficiently with low electric power. This paper also involves the effect of particle size of Si and C initial reactant powders on conversion efficiency into SiC and also on particle size of SiC powder fabricated by this method.

Production of Al2O3/SiC Nanoparticles from Rice Husk Ash by Self-Propagating High-Temperature Synthesis Process and Ball Milling

2017 ◽  
Vol 904 ◽  
pp. 93-97 ◽  
Author(s):  
Morteza Hoseini ◽  
Ghasem Dini ◽  
Azam Fatemi
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Ball Milling ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Synthesis Process ◽  
Average Particle ◽  
Temperature Synthesis ◽  
Sic Nanoparticles ◽  
High Temperature Synthesis

In this study, silica obtained from the rice husk was used to synthesis of Al2O3/SiC nanoparticles. For this reason, the ash obtained from the burning of the rice husk which contains more than 93 wt. % silica, aluminum and carbon powders with the molar ratios of 3:4:6 were mixed and then compacted into pellets by using a cylindrical die under a pressure 50MPa. In order to conduct the self-propagating high-temperature synthesis (SHS), the produced pellets were placed in an electrical furnace at 850°C under the argon gas atmosphere. Then, a planetary ball milling for 4 to 24h was used to decrease the particle size of the synthesized composite. The results of XRF, XRD, SEM and DLS investigations shown that the rice husk ash can be used to fabricate Al2O3/SiC nanoparticles with an average particle size of about 80 to 65nm via SHS process and ball-milling for 12 to 24h.

Features of Regularities of Ni3Al Intermetallic Compound High-Temperature Synthesis in a Powder Mixture (3Ni + Al) under Pressure

2018 ◽  
Vol 938 ◽  
pp. 41-45
Author(s):  
K.O. Akimov ◽  
E.N. Boyangin ◽  
Vladimir E. Ovcharenko
Keyword(s):  
High Temperature ◽  
Intermetallic Compound ◽  
Powder Mixture ◽  
Exothermic Reaction ◽  
Strength Properties ◽  
Grain Structure ◽  
Temperature Synthesis ◽  
Compound Formation ◽  
High Temperature Synthesis ◽  
Intermetallic Compound Formation

The results of investigation of the time and power parameters influence of high-temperature synthesis under pressure on the grain structure formation and strength properties of the Ni3Al intermetallic compound are presented and discussed. Dependences of the grain size in the intermetallic compound synthesized under pressure and its strength properties on the value of the preload on the initial powder mixture (3Ni + Al) and on the delay time of pressure application to the thermoreacting system were determined from the time of initiation of intermetallic compound formation volumetric exothermic reaction.

Self-Propagating High-Temperature Synthesis of TiB2-Ti(C, N) Cermets Composite Powder

2012 ◽  
Vol 468-471 ◽  
pp. 1247-1250 ◽  
Author(s):  
Fang Yang ◽  
Zhi Meng Guo ◽  
Jun Jie Hao ◽  
Yong Liang Shi
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Ni Addition ◽  
Brittle Phase

The ultra-fine TiB2-Ti(C, N) composite powders were prepared by self-propagating high-temperature synthesis (SHS) with Ti, BN and C powders as its starting materials. The morphology of the products was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed the composite powders were consisted of the mainly phases Ti(C, N), TiB2 and a small amount of TiN phase. With the Ni addition, the brittle phase Ni3B was appeared. SEM results revealed that the composite powders had a uniform particle size, a round grain-shaped structure and a narrow size distribution and the average particle size of which is less than 1μm.

Microstructure of intermetallic-matrix composites produced in situ by self-propagating high-temperature synthesis

1994 ◽  
Vol 52 ◽  
pp. 708-709
Author(s):  
C. P. Doğan ◽  
D. E. Alman
Keyword(s):  
High Temperature ◽  
Exothermic Reaction ◽  
Ceramic Composites ◽  
Matrix Composites ◽  
Temperature Synthesis ◽  
Intermetallic Matrix ◽  
High Temperature Synthesis ◽  
Wide Range ◽  
Intermetallic Matrix Composites

Self-propagating, high-temperature synthesis (SHS) is one method of material production in which elemental constituents are ignited, initiating a self-sustaining, exothermic reaction that results in their transformation into intermetallic and ceramic compounds. In addition, several reactions can be initiated within a single body to form intermetallic-intermetallic, intermetallic-ceramic, or ceramic-ceramic composites in situ. The driving force for the reactions is the negative heats of mixing of the forming compounds, which results in the liberation of heat. The obvious advantages of SHS processing are that it presents an opportunity to produce near net-shape advanced materials and composites with a high level of purity in a relatively low-cost and energy efficient manner.At the U.S. Bureau of Mines, we are actively involved in the SHS processing of a wide range of singlephase intermetallic and intermetallic-matrix composites: TiAl, TiAl+TiB2, TiAl+TiC, TiAl+Ti5Si3, MoSi2+SiC. One key element of our study is a thorough understanding of the effect of processing variables, such as composition, temperature, pressure, time, powder morphology, etc., on the microstructure, and hence the properties, of these materials.

Preparation of ZrC Powder by Self-Propagating High-Temperature Synthesis

2009 ◽  
Vol 66 ◽  
pp. 258-261 ◽  
Author(s):  
Jing Li ◽  
Zheng Yi Fu ◽  
Jin Yong Zhang ◽  
Hao Wang ◽  
Wei Min Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Exothermic Reaction ◽  
Fine Powder ◽  
Adiabatic Temperature ◽  
Electron Micrograph ◽  
Scanning Electron Micrograph ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Average Size ◽  
Scanning Electron

ZrC fine powder has been prepared by self-propagating high-temperature synthesis (SHS) using exothermic reaction of ZrO2-C-Mg system. By theoretical calculating, the adiabatic temperature (Tad) for the system is about 2235K enough to react as SHS process. The Tad observed during experiment is 1850K. The results show that high pure ZrC powder is obtained with appropriate Mg contents. The scanning electron micrograph shows that the average size of ZrC particles is about 2μm.

Magnesium reduction of WO3 in a self-propagating high-temperature synthesis (SHS) process

1995 ◽  
Vol 10 (4) ◽  
pp. 795-797 ◽  
Author(s):  
Seog Gueon Ko ◽  
Chang Whan Won ◽  
Byong Sun Chun ◽  
H.Y. Sohn
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
High Purity ◽  
Exothermic Reaction ◽  
The Self ◽  
Molar Ratio ◽  
Temperature Synthesis ◽  
Complete Reduction ◽  
High Temperature Synthesis ◽  
Hcl Solution

High-purity tungsten was prepared by the self-propagating high-temperature synthesis (SHS) process from a mixture of WO3 and Mg. The MgO in the product was leached with an HCl solution. The complete reduction of WO3 required a 33% excess of magnesium over the stoichiometric molar ratio Mg/WO3 of 3. The product tungsten had a purity of 99.980% which was higher than that of the reactant WO3. This is because the impurities were either volatilized at the high temperatures generated during the rapid exothermic reaction or dissolved into the HCl solution during leaching.

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