Observations on combustion front propagation in self-propagating high-temperature synthesis process producing refractory ceramics

2002 ◽  
Vol 19 (3) ◽  
pp. 400-405
Author(s):  
Chang-Ho Park ◽  
Tae-Sung Kang ◽  
Sang Hwan Kim
Keyword(s):  
High Temperature ◽  
Combustion Front ◽  
Front Propagation ◽  
Synthesis Process ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Refractory Ceramics

scholarly journals High-Temperature Synthesis of Metal–Matrix Composites (Ni-Ti)-TiB2

2021 ◽  
Vol 11 (5) ◽  
pp. 2426
Author(s):  
Vladimir Promakhov ◽  
Alexey Matveev ◽  
Nikita Schulz ◽  
Mikhail Grigoriev ◽  
Andrey Olisov ◽  
...  
Keyword(s):  
High Temperature ◽  
Composite Materials ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Average Particle Size ◽  
Synthesis Process ◽  
Average Particle ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

Currently, metal–matrix composite materials are some of the most promising types of materials, and they combine the advantages of a metal matrix and reinforcing particles/fibres. Within the framework of this article, the high-temperature synthesis of metal–matrix composite materials based on the (Ni-Ti)-TiB2 system was studied. The selected approaches make it possible to obtain composite materials of various compositions without contamination and with a high degree of energy efficiency during production processes. Combustion processes in the samples of a 63.5 wt.% NiB + 36.5 wt.% Ti mixture and the phase composition and structure of the synthesis products were researched. It has been established that the synthesis process in the samples proceeds via the spin combustion mechanism. It has been shown that self-propagating high-temperature synthesis (SHS) powder particles have a composite structure and consist of a Ni-Ti matrix and TiB2 reinforcement inclusions that are uniformly distributed inside it. The inclusion size lies in the range between 0.1 and 4 µm, and the average particle size is 0.57 µm. The obtained metal-matrix composite materials can be used in additive manufacturing technologies as ligatures for heat-resistant alloys, as well as for the synthesis of composites using traditional methods of powder metallurgy.

scholarly journals SHS robust modes to restore molybdenum by combustion wave in MoO3 – Al system

2020 ◽  
Vol 15 (4) ◽  
pp. 27-32
Author(s):  
Irina V. Milyukova ◽  
Marina P. Boronenko
Keyword(s):  
Spectral Analysis ◽  
High Temperature ◽  
Combustion Wave ◽  
Synthesis Process ◽  
Temperature Synthesis ◽  
Preliminary Heating ◽  
X Ray ◽  
Molybdenum Metal ◽  
High Temperature Synthesis ◽  
Oxide Phases

The work is devoted to the technology for the reduction of molybdenum from oxides by the method of self-propagating high-temperature synthesis in the MoO3 AI system with the addition of aluminum. The experiment was carried out in two modes: in a reactor at different pressures without preliminary heating and in a furnace in air until the initiation of the SH-synthesis process. Samples of molybdenum metal were obtained in different synthesis modes. X-ray phase and X-ray spectral analysis showed that molybdenum is the main phase in the synthesized samples. The presence of slag oxide phases Al2O3 and MoO2 was detected.

scholarly journals Self-Propagating High-Temperature Synthesis under the Conditions of Rotation and Characteristic Heat and Concentration Limits on the Example of Oxide Systems

2011 ◽  
Vol 13 (3-4) ◽  
pp. 149
Author(s):  
Georgij I. Ksandopulo
Keyword(s):  
High Temperature ◽  
Combustion Front ◽  
Temperature Synthesis ◽  
Oxide Systems ◽  
High Temperature Synthesis ◽  
Adiabatic Regime ◽  
Continuous Technology ◽  
Technology Of Production ◽  
Concentration Limits ◽  
Melted Metal

Potential economic possibility of using centrifugal force for production of noble ferroalloys is shown. Connected with this process, the limits of stable combustion are conditioned by formation of adiabatic regime of combustion due to the effect of acceleration of the combustion front by centrifuged particles of melted metal product. There appears the possibility to create a continuous technology of production of ferroalloys on the basis of aluminothermy and of significantly decreased low limit concentration of the sought for metal in the initial row material.

Immobilization of Radioactive Wastes into Perovskite Synrock by the SHS Method

2005 ◽  
Vol 475-479 ◽  
pp. 1627-1630 ◽  
Author(s):  
Rui Zhu Zhang ◽  
Zhi Meng Guo ◽  
Cheng Chang Jia ◽  
Guangfeng Lu
Keyword(s):  
High Temperature ◽  
Synthesis Process ◽  
Temperature Synthesis ◽  
Geological Disposal ◽  
Major Phase ◽  
Leach Rate ◽  
High Temperature Synthesis ◽  
Waste Loading ◽  
Shs Method

This paper researched the fabrication of perovskite synrock by self-propagating high temperature synthesis (SHS) and the characterization of the products. This synthesis process is simpler, the fabricated synrock can immobilize waste loading up to 35wt% SrO with satisfied physical properties (density>4.2g•cm-3, open porosity<0.2%, Leach rate<1.0 g•m-2•d-1). The structure analyses by XRD and SEM/EDS show that the major phase is perovskite which well agrees with the design. It proves that SHS offer a suitable Sr-waste synroc which is favorable for geological disposal.

FGM Fabrication by Combustion Synthesis

MRS Bulletin ◽  
1995 ◽  
Vol 20 (1) ◽  
pp. 52-53 ◽  
Author(s):  
Gregory C. Stangle ◽  
Yoshinari Miyamoto
Keyword(s):  
High Temperature ◽  
Combustion Synthesis ◽  
Volume Fraction ◽  
Synthesis Process ◽  
Composition Gradient ◽  
Synthesis Methods ◽  
High Temperature Synthesis ◽  
Exothermic Chemical Reaction ◽  
Reactant Powder ◽  
Refractory Ceramics

FGMs have been fabricated using the combustion synthesis (or self-propagating high-temperature synthesis (SHS)) process by exploiting a rapid and exothermic chemical reaction, in order to synthesize some (or all) of the constituents in an FGM to simultaneously increase its density. The thermal energy required to drive the process is derived from this internal, chemical source, rather than from an external and usually expensive source (e.g., a furnace). The combustion synthesis process is a powder-based process that has been used to synthesize over 300 compounds, and is particularly useful in preparing materials such as highly refractory ceramics and high-temperature intermetallics that are difficult to prepare by other synthesis methods. In addition, the process can be used to prepare ceramic-metal and ceramic-intermetallic composite materials. As a result, only slight modifications of the combustion synthesis are required to prepare functionally gradient materials from these same combinations of materials.Sample preparation begins by the creation of a series of mixtures from the powders that will react to form the constituent materials of the FGM sample. Each of these mixtures contains a slightly different percentage of reactants, so that each mixture will yield its own (predetermined) volume fraction of each of its constituents, following the combustion synthesis process. Prior to the combustion step, the samples are assembled by stacking layers of each of the reactant powder mixtures in appropriate amounts, in such a way that the multilayered powder mixture will faithfully produce the composition gradient that is required in the resultant FGM.

The Mechanism of the Formation of MoSi2 by Self-Propagating High-Temperature Synthesis

2007 ◽  
Vol 280-283 ◽  
pp. 1467-1470 ◽  
Author(s):  
Jian Ying Gao ◽  
Wan Jiang ◽  
Gang Wang
Keyword(s):  
High Temperature ◽  
Combustion Front ◽  
Experimental Results ◽  
Reactive Diffusion ◽  
Temperature Synthesis ◽  
Precipitation Mechanism ◽  
High Temperature Synthesis

A combustion front quenching (CFQ) technique was used to investigate the mechanism of selfpropagating high-temperature synthesis (SHS) of MoSi2 from Mo and Si powders. Based on the experimental results, a combination of reactive diffusion and dissolution-precipitation mechanism of the formation of MoSi2 was proposed, and a model corresponding to this mechanism was drawn.

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