scholarly journals Self-propagating high-temperature synthesis of refractory powder materials based on zirconium diboride obtained from boron-containing mineral raw materials of the Republic of Kazakhstan

2018 ◽  
pp. 4-11
Author(s):  
Aisulu Batkal ◽  
Gulnaz Temirlanova ◽  
Elaman Satybaldiyev ◽  
Aizhan Seydualieva ◽  
Roza Abdulkarimova
Keyword(s):  
High Temperature ◽  
Raw Materials ◽  
Synthesis Method ◽  
Zirconium Diboride ◽  
Powder Materials ◽  
Temperature Synthesis ◽  
Refractory Powder ◽  
High Temperature Synthesis ◽  
Methods Of Synthesis ◽  
The Republic

The goal of the present work is the synthesis of the refractory zirconium diboride powder in the combustion mode. One of the most effective methods of synthesis of the refractory zirconium diboride powder is the self-propagating high-temperature synthesis method (SHS) with a preliminary mechanical activation of the initial components. Initial components of the SH-synthesis are borate ore, zircon, aluminum powder and magnesium. After the SH-synthesis obtained products were processed by 37.5% HCl and were washed with distilled water. Final composition and microstructure of SHS products were investigated with X-ray phase analysis and SEM. Boron-containing SHS-powders can be used as bio-protection in nuclear engineering, production of abrasive powders, ceramic, composite materials and coatings.

Self-propagating high-temperature synthesis microalloying of MoSi2 with Nb and V

2003 ◽  
Vol 18 (8) ◽  
pp. 1842-1848 ◽  
Author(s):  
F. Maglia ◽  
C. Milanese ◽  
U. Anselmi-Tamburini ◽  
Z. A. Munir
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Tetragonal Phase ◽  
Synthesis Method ◽  
The Self ◽  
Alloying Elements ◽  
Alloying Element ◽  
Temperature Synthesis ◽  
Starting Mixture ◽  
High Temperature Synthesis

Microalloying of MoSi2 to form Mo(1−x)MexSi2 (Me = Nb or V) was investigated by the self-propagating high-temperature synthesis method. With alloying element contents up to 5 at.%, a homogeneous C11b solid solution was obtained. For higher contents of alloying elements, the product contained both the C11b and the hexagonal C40 phases. The relative amount of the C40 phase increases with an increase in the content of alloying metals in the starting mixture. The alloying element content in the hexagonal C40 Mo(1−x)MexSi2 phase was nearly constant at a level of about 12 at.% for all starting compositions. In contrast, the content of the alloying elements in the tetragonal phase is considerably lower (around 4 at.%) and increases slightly as the Me content in the starting mixture is increased.

scholarly journals Direct observation of the formation and stabilization of metallic nanoparticles on carbon supports

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhennan Huang ◽  
Yonggang Yao ◽  
Zhenqian Pang ◽  
Yifei Yuan ◽  
Tangyuan Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Metallic Nanoparticles ◽  
Synthesis Method ◽  
Md Simulations ◽  
Graphite Substrate ◽  
Carbon Supports ◽  
Temperature Synthesis ◽  
Excellent Thermal Stability ◽  
High Temperature Synthesis ◽  
Underlying Mechanisms

AbstractDirect formation of ultra-small nanoparticles on carbon supports by rapid high temperature synthesis method offers new opportunities for scalable nanomanufacturing and the synthesis of stable multi-elemental nanoparticles. However, the underlying mechanisms affecting the dispersion and stability of nanoparticles on the supports during high temperature processing remain enigmatic. In this work, we report the observation of metallic nanoparticles formation and stabilization on carbon supports through in situ Joule heating method. We find that the formation of metallic nanoparticles is associated with the simultaneous phase transition of amorphous carbon to a highly defective turbostratic graphite (T-graphite). Molecular dynamic (MD) simulations suggest that the defective T-graphite provide numerous nucleation sites for the nanoparticles to form. Furthermore, the nanoparticles partially intercalate and take root on edge planes, leading to high binding energy on support. This interaction between nanoparticles and T-graphite substrate strengthens the anchoring and provides excellent thermal stability to the nanoparticles. These findings provide mechanistic understanding of rapid high temperature synthesis of metal nanoparticles on carbon supports and the origin of their stability.

The Use of Combustion Reactions for Processing Mineral Raw Materials: Metallothermy and Self-propagating High-temperature Synthesis (Review)

2015 ◽  
Vol 47 (1) ◽  
pp. 58-66 ◽  
Author(s):  
Farit Kh. Urakaev ◽  
Kenzhebek A. Akmalaev ◽  
Eljan S. Orynbekov ◽  
Beykut D. Balgysheva ◽  
Dinar N. Zharlykasimova
Keyword(s):  
High Temperature ◽  
Raw Materials ◽  
Temperature Synthesis ◽  
Mineral Raw Materials ◽  
High Temperature Synthesis

A self-propagating high-temperature synthesis method for synthesis of zinc oxide powder

2009 ◽  
Vol 467 (1-2) ◽  
pp. 514-523 ◽  
Author(s):  
Chyi-Ching Hwang ◽  
Cheng-Shiung Lin ◽  
Gaw-Pying Wang ◽  
Cheng-Hsiung Peng ◽  
Shyan-Lung Chung
Keyword(s):  
Zinc Oxide ◽  
High Temperature ◽  
Synthesis Method ◽  
Oxide Powder ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Zinc Oxide Powder

Production of superconducting NbN thin plate and wire by the self-propagating high-temperature synthesis method

1993 ◽  
Vol 12 (7) ◽  
pp. 500-501 ◽  
Author(s):  
M. Ohyanagi ◽  
M. Koizumi ◽  
K. Tanihata ◽  
Y. Miyamoto ◽  
0. Yamada ◽  
...  
Keyword(s):  
High Temperature ◽  
Thin Plate ◽  
Synthesis Method ◽  
The Self ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

scholarly journals The application of self-propagating hightemperature synthesis to obtain a protective-strengthening alumina-silica coatings

2019 ◽  
Vol 55 (2) ◽  
pp. 240-246
Author(s):  
R. Yu. Popov ◽  
E. O. Bohdan ◽  
E. M. Dyatlova ◽  
M. V. Komar
Keyword(s):  
High Temperature ◽  
Raw Materials ◽  
Operating Temperature ◽  
Thermal Unit ◽  
Ceramic Factory ◽  
Coating Structure ◽  
Temperature Synthesis ◽  
Silica Coatings ◽  
Hardening Coatings ◽  
High Temperature Synthesis

This article shows the possibility of using the method of self-propagating high-temperature synthesis to obtain protective and hardening coatings for the lining of various thermal installations. The development of compositions of ceramic masses for the production of SHS coatings was carried out on the basis of aluminum powder, clay raw materials, exhausting and fluxing components as well as mineralizing additives. The prepared suspension including pre-prepared and thoroughly mixed raw materials was applied with a brush or a spray gun onto the previously cleaned and moistened surface of an aluminosilicate refractory. The firing of the coating was carried out in accordance with the mode of removing the thermal unit at the operating temperature. The temperature of the initiation of the SHS process, previously established using differential thermal analysis, was in the range of 570–720 °C and depended on the chemical composition of the charge. It has been established that the presence of crystalline phases of silica, corundum, hematite and a number of solid solutions (mainly calcium and sodium aluminosilicates) in the coating structure provides the necessary combination of the thermomechanical and thermophysical characteristics of the coatings. On the basis of the conducted research, the expediency of applying the technology of self-propagating high-temperature synthesis for the production of protective and hardening coatings on the lining of thermal units is demonstrated, which is confirmed by industrial tests in the conditions of the Minsk Ceramic Factory OJSC «Keramin».

Preparation of Submicron Metastable Spherical β-Bi2O3 Particles by Self-Propagating High-Temperature Synthesis Method

2019 ◽  
Vol 19 (11) ◽  
pp. 7436-7441
Author(s):  
Chu Zhang ◽  
Qi-Yu Wang ◽  
Ming-De Li ◽  
Guo-Dong Zhang
Keyword(s):  
High Temperature ◽  
High Efficiency ◽  
Synthesis Method ◽  
Reaction System ◽  
Average Diameter ◽  
Spherical Particles ◽  
Molar Ratio ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
One Step

Sub-micrometer particles of β-Bi2O3 were successfully synthesized via a one-step self-propagating high-temperature synthesis (SHS) method for the first time. The experiments were carried out in the air at room temperature. The products were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). In this study, three experiments were designed to optimize the heat source, Bi source and additive for the reaction system. Results showed that the system composed of Al, Bi2O3 and Al2O3 powders could synthesize monodisperse high-purity β-Bi2O3 spherical particles with the average diameter of 369 nm and the as-prepared products kept stable after being exposed in air for one month. Then, the influences of the ratio of the three components on system were investigated. Interestingly, it was found that a slight adjustment on the ratio of Al:Bi2O3:Al2O3 had significant effects on the reactions happening in a system. Specifically, when the amount of Al2O3 exceeds the molar ratio of 2:1:1 (Al:Bi2O3:Al2O3), it is difficult to ignite the reaction system; when the amount is less than 2:1:0.5, the reaction system becomes too violent to obtain pure products. However, there are no obvious differences on the morphology and structure of final products with the two ratios because of few changes in adiabatic temperature. Preparation of β-Bi2O3 by SHS technique enjoying many advantages, such as high efficiency, inexpensive experimental equipment and simple processes, would has a promising prospect for industrial application.

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