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».

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

scholarly journals Preparation of AlB12 Powder by Self-Propagating High-Temperature Synthesis (SHS)

2021 ◽  
Author(s):  
Chao Wang ◽  
Xiaoming Cao ◽  
Mengge Dong ◽  
Lu Zhang ◽  
Jianxing Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Phase Analysis ◽  
Raw Materials ◽  
The Self ◽  
Temperature Synthesis ◽  
Root Cause ◽  
High Temperature Synthesis

<p>Self-propagating high-temperature synthesis (SHS) process is used to prepare AlB<sub>12</sub>. The phase analysis results of preparing AlB<sub>12</sub> with Al and B<sub>2</sub>O<sub>3</sub> as raw materials show that: under air and argon conditions, the self-propagating and acid-washed self-propagating powders all have α-Al<sub>2</sub>O<sub>3</sub> impurities; Mg, Al and B<sub>2</sub>O<sub>3</sub> are used as raw materials. The phase analysis results of the preparation of AlB<sub>12</sub> show that under argon conditions, the self-propagating and acid-washed self-propagating powder has unremovable MgAl<sub>2</sub>O<sub>4</sub> impurities; the root cause of the low purity of AlB<sub>12</sub> prepared by the self-propagating method is that there are unremovable impurities exist.</p>

scholarly journals A study of ceramic-lined composite steel pipes prepared by SHS centrifugal-thermite process

2016 ◽  
Vol 48 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Yuxin Li ◽  
Letao Jiang ◽  
Qing Lu ◽  
Peikang Bai ◽  
Bin Liu ◽  
...  
Keyword(s):  
Phase Separation ◽  
High Temperature ◽  
Transition Layer ◽  
Raw Materials ◽  
Ceramic Layer ◽  
Steel Pipe ◽  
Temperature Synthesis ◽  
Al2o3 Ceramic ◽  
Steel Pipes ◽  
High Temperature Synthesis

Al2O3 ceramic-lined steel pipe was produced by self-propagating high-temperature synthesis centrifugal thermite process (SHS C-T process) from Fe2O3 and Al as the raw materials. The composition, phase separation and microstructures were investigated. The result showed the ceramic lined pipe is composed of the three main layers of various compositions, which were subsequently determined to be Fe layer, the transition layer and the ceramic layer. Fe layer is composed of austenite and ferrite, the transition layer consisted of Al2O3 ceramic and Fe, the ceramic layer consisted of the dendritic-shaped Al2O3 and the spinel-shaped structured FeAl2O4.

scholarly journals Preparation of AlB12 Powder by Self-Propagating High-Temperature Synthesis (SHS)

2021 ◽  
Author(s):  
Chao Wang ◽  
Xiaoming Cao ◽  
Mengge Dong ◽  
Lu Zhang ◽  
Jianxing Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Phase Analysis ◽  
Raw Materials ◽  
The Self ◽  
Temperature Synthesis ◽  
Root Cause ◽  
High Temperature Synthesis

<p>Self-propagating high-temperature synthesis (SHS) process is used to prepare AlB<sub>12</sub>. The phase analysis results of preparing AlB<sub>12</sub> with Al and B<sub>2</sub>O<sub>3</sub> as raw materials show that: under air and argon conditions, the self-propagating and acid-washed self-propagating powders all have α-Al<sub>2</sub>O<sub>3</sub> impurities; Mg, Al and B<sub>2</sub>O<sub>3</sub> are used as raw materials. The phase analysis results of the preparation of AlB<sub>12</sub> show that under argon conditions, the self-propagating and acid-washed self-propagating powder has unremovable MgAl<sub>2</sub>O<sub>4</sub> impurities; the root cause of the low purity of AlB<sub>12</sub> prepared by the self-propagating method is that there are unremovable impurities exist.</p>

scholarly journals Combustion Synthesis of Composition Ferroalloys

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2117
Author(s):  
Mansur Ziatdinov ◽  
Alexander Zhukov ◽  
Vladimir Promakhov
Keyword(s):  
High Temperature ◽  
Raw Materials ◽  
Ferroalloy Production ◽  
Production Cycle ◽  
Practical Implementation ◽  
Exchange Reactions ◽  
Temperature Synthesis ◽  
New Approach ◽  
High Temperature Synthesis ◽  
Steel Alloying

The main objective of this paper is to present results of the research in the development of a specialized self-propagating high-temperature synthesis (SHS) technology for ferroalloy composites, as applied to steelmaking. The problem of creating such a production cycle has been solved by developing a new approach to the practical implementation of self-propagating high-temperature synthesis, as applied to metallurgy. The metallurgical variation of SHS is based on the use of different metallurgic alloys (including waste in the form of dust from ferroalloy production) as basic raw materials in the new process. Here, the process of synthesis by combustion is realized through exothermic exchange reactions. The process produces a composite, based on inorganic compositions with a bond of iron and/or alloy based on iron. It has been shown that in terms of the aggregate state of initial reagents, metallurgical SHS processes are either gasless or gas-absorbing. Combustion regimes significantly differ when realized in practice. To organize the metallurgical SHS process in weakly exothermic systems, different variations of the thermal trimming principle are used. In the present study, self-propagating high-temperature synthesis of ferrovanadium nitride, which is widely used in steel alloying, was investigated. It has been shown that the phase composition of the initial alloy has a profound impact on the regular patterns in ferrovanadium combustion in nitrogen and on the mechanism itself. During the nitriding of σ-(Fe-V), process activation is taking place. The activation is due to the transformation of the intermetallide into an α-solid solution, when the temperature of phase transition is reached (~1200 °C). The composite structure of the products of ferrovanadium is nitriding by the fusion of particles-droplets composed of molten Fe and solid VN.

Self-Propagating High-Temperature Synthesis of Ni-Cu-Zn Ferrites with Alternative Fuel of Carbon Powder

2014 ◽  
Vol 981 ◽  
pp. 887-890
Author(s):  
Zhen Hua Wang ◽  
Jiu Xing Jiang ◽  
Chang Long Tan ◽  
Zhi Han Zhu ◽  
Fan Xu
Keyword(s):  
High Temperature ◽  
Raw Materials ◽  
Spinel Phase ◽  
Carbon Powder ◽  
Temperature Synthesis ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Zn Ferrite ◽  
Mass Fractions ◽  
Microstructure Density

Ni-Cu-Zn ferrite powders were prepared by self-propagating high-temperature synthesis (SHS) using carbon powder with different mass fractions as fuel. The effects of carbon content in the raw materials on the phase composition, microstructure, density and magnetic property of the Ni-Cu-Zn powders were investigated by X-ray diffractometry(XRD), scanning electron microscope(SEM) and vibrating sample magnetometer(VSM), respectively. The results show that the use of carbon as a fuel brings no other impurities and improved the permeability. The single spinel phase powder was obtained when the precursor materials with a carbon powder of 5% in mass were used.

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.

Alumina Whiskers Formation during Self-Propagation High-Temperature Synthesis

2007 ◽  
Vol 280-283 ◽  
pp. 1021-1022 ◽  
Author(s):  
Ling Zhen Zhang ◽  
Chun Chao Zhang
Keyword(s):  
Titanium Dioxide ◽  
High Temperature ◽  
Growth Mechanism ◽  
Raw Materials ◽  
Combustion Process ◽  
The Self ◽  
Combustion Mode ◽  
Temperature Synthesis ◽  
Aluminum Powders ◽  
High Temperature Synthesis

In this paper, the SHS process was accomplished using titanium dioxide and aluminum powders as raw materials. It was found that the combustion process exhibited the self-spiral combustion mode and alumina whisker had formed. The morphology, microstructure and growth mechanism of alumina whisker were investigated.

scholarly journals Preparation of ZrB2-MoSi2 high oxygen resistant coating using nonequilibrium state powders by self-propagating high-temperature synthesis

2021 ◽  
Vol 10 (5) ◽  
pp. 1011-1024
Author(s):  
Menglin Zhang ◽  
Xuanru Ren ◽  
Mingcheng Zhang ◽  
Songsong Wang ◽  
Li Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Raw Materials ◽  
Nonequilibrium State ◽  
High Oxygen ◽  
Glass Layer ◽  
Composite Powders ◽  
Temperature Synthesis ◽  
Oxidation Activity ◽  
High Temperature Synthesis ◽  
Oxidation Stage

AbstractTo achieve high oxygen blocking structure of the ZrB2-MoSi2 coating applied on carbon structural material, ZrB2-MoSi2 coating was prepared by spark plasma sintering (SPS) method utilizing ZrB2-MoSi2 composite powders synthesized by self-propagating high-temperature synthesis (SHS) technique as raw materials. The oxygen blocking mechanism of the ZrB2-MoSi2 coatings at 1973 K was investigated. Compared with commercial powders, the coatings prepared by SHS powders exhibited superior density and inferior oxidation activity, which significantly heightened the structural oxygen blocking ability of the coatings in the active oxidation stage, thus characterizing higher oxidation protection efficiency. The rise of MoSi2 content facilitated the dispersion of transition metal oxide nanocrystals (5–20 nm) in the SiO2 glass layer and conduced to the increasing viscosity, thus strengthening the inerting impact of the compound glass layer in the inert oxidation stage. Nevertheless, the ZrB2-40 vol%MoSi2 coating sample prepared by SHS powders presented the lowest oxygen permeability of 0.3% and carbon loss rate of 0.29×10−6 g·cm−2·s−1. Owing to the gradient oxygen partial pressure inside the coatings, the Si-depleted layer was developed under the compound glass layer, which brought about acute oxygen erosion.

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